The authors thank Prof. Ralph Weissleder, Dr. Pat Zanzonico, and Dr. NagaVaraKishore Pillarsetty for helpful conversations and the NIH for funding (BMZ: 1K99CA178205-01A1)

倫理STATEMENT：記載のin vivo動物実験のすべてが承認されたプロトコルとメモリアルスローンケタリングがんセンター施設内動物管理使用委員会（IACUC）の倫理指針の下で実施した。 TZ-BN-NOTAの1の合成<ol><li>小さ ​​な反応容器中で、600μlの飽和NaHCO 3緩衝液（0.1M、pHが8.1）に7mgのNH 2 -Bn-NOTA（1.25×10 -2ミリモル）を溶解する。溶液のpHを確認してください。必要に応じて、0.1 MのNa 2 CO 3の少量のアリコートを用いて8.1に溶液のpHを調節する。 </li><li> 1.7ミリリットルのマイクロ遠心チューブに0.5mgのTZ-NHS（1.25×10 -3 mmol）のNH 2 -Bn-NOTAソリューションを追加します。 注：TZ-NHSは、乾式を秤量または乾燥DMFまたはDMSO（&lt;50μL）のストック溶液から追加することができます。 </li><li>得られた反応溶液を室温で30分間反応させる穏やかに撹拌しながら。 </li><li> 30分後、未反応のNH 2 -Bn-NOTAを除去し、逆相C 18 HPLCクロマトグラフィーを用いて生成物を精製する。 TZ-NHSおよびTZ-BN-NOTAは最高の525の波長で監視されながら、NH 2 -Bn-NOTAは、254nmの波長でモニターすることができます。 注：保持時間は、明らかに、各研究室（ポンプ、カラム、チューブなど ）のHPLC機器設定に大きく依存している。 100〜100のMeCN / H 2 O（0.1％TFA両方）：0のMeCN / H 2 O 25分および分析4.6×250ミリメートルC 18カラムを使用した0の勾配は場合は、例を提示する、Tzを-Bnは、NOTA、Tzを-NHSおよびNH 2 -Bn-NOTAの保持時間は、それぞれ、約15分、16.5分、および10分であろう。生成物は、単一の実行またはセミ分取または分取C 18 HPLCカラムを使用して複数の実行のいずれかの他の反応成分から精製することができる。1 H-NMR、肛門ytical HPLCおよびESI-MS完了Tzを-Bnは、NOTA前駆体の純度を確認するために使用することができるすべての方法である。11 </li><li>液体窒素を使用して収集HPLC溶出液を凍結する。 </li><li>不透明なアルミホイルで凍結されたコレクションチューブを包みます。 </li><li> HPLC移動相を除去するために凍結乾燥容器のO / Nで凍結されたコレクションチューブを置きます。 </li><li> -80℃で暗所に精製された生成物（固体明るいピンク）を保管してください。 注：この手順で許容停止点である。完成Tzを-Bnは、NOTA前駆体は、これらの条件下で少なくとも1年間安定である。 </li></ol> huA33-TCO免疫複合の調製<ol><li> 1.7ミリリットルマイクロ遠心チューブでは、1 mg / mlの乾燥DMF中のTCO-NHSの（2.7 mM）の溶液を調製。 </li><li> 1.7 mlのマイクロ遠心チューブにおいて、リン酸緩衝生理食塩水1mlにhuA33の2mg / mlの（13.3μM）溶液を調製し、pHを7.4（0.01 M PO 4 3- </sub&gt; 0.154 MのNaCl）。 </li><li> 0.1 MのNa 2 CO 3の少量のアリコート（&lt;5μl）を使用して、8.8から9.0への抗体溶液のpHを調整。 pHを監視するために微小電極でpH試験紙またはpH計のいずれかを使用し、pHが9.0を超えて上昇することを可能にしないように注意してください。 </li><li>抗体溶液は、適切なpHであると、活性化エステルの8モル当量に対応するTCO-NHS溶液の容量を追加する。例えば、2 mg / mlのhuA33抗体溶液（1.33×10 -8モルhuA33）1mlに1mg / mlのTCO-NHSの溶液（1.07×10 -7モルTCO-NHS）7.9μlを添加する。溶液中で5体積％DMFを超えないようにしてください。 </li><li>静かにマイクロ遠心チューブを数回反転させた溶液を混合。 </li><li>不透明なアルミホイルでマイクロ遠心チューブを包みます。 </li><li>ソリューションは、穏やかに撹拌しながら室温で1時間インキュベートすることを許可する。 </li><li>室温で1時間後、プレパック使い捨てSIZを使用して生じた免疫複合体を精製しE除外脱塩カラム。貯蔵中のカラム上に存在する任意の防腐剤を除去するために供給者によって記載されているように、まず、サイズ排除カラムをリンスする。その後、1.5mlの0.9％滅菌生理食塩水でカラムを洗い流し、サイズ排除カラムに反応混合物を追加し、続いて溶離液として0.9％滅菌生理食塩水2 mlを使用して製品を収集する。 注：このステップは2ミリリットルソリューションとして完成huA33-TCOが得られます。 </li><li> UV-Vis分光光度計に生じたhuA33-TCOの濃度を測定します。 </li><li>より高い濃度が望まれる場合には50,000分子量カットオフ遠心フィルターユニットを用いhuA33、TCO液を濃縮する。 注：それはhuA33と他のよく知られた種々の抗体（ 例えば、ベバシズマブ、トラスツズマブ、セツキシマブ、およびJ591）が集中しているのは非常に寛容である一方で、凝集および沈殿が他のケースでは濃度に発生する可能性があることに注意することが重要である。このPROCEDを試みる研究者新しい抗体とのUREは文献または抗体を集中させるかどうかに関しては問題の抗体の独自の知識を信頼する必要があります。 </li><li>暗闇の中で4℃で完了しhuA33-TCOの免疫複合体を保管してください。 注：この手順で許容停止点である。完成したmAbを、T​​COコンジュゲートは、これらの保存条件下で少なくとも3ヶ月間安定であるべきである。 </li></ol> 3. TZ-BN-NOTAの64 Cuの放射性標識注：プロトコルのこの手順では、放射能の取り扱いと操作を含む。または放射能を持つ他の作業を行う - - これらの手順を実行する前に研究者は、自宅の機関の放射線安全課に相談してください。電離放射線への暴露を最小限に抑えるために可能なすべての手順を実行します。 <ol><li> 1.7ミリリットルマイクロ遠心チューブでは、0.5 mg / mlの（723μM）TZ-BN-NOTAの溶液を調製。 </li><li> 1.7ミリリットルのMicroCでentrifugeチューブ、0.2 M NH 4 OAcのpHが5.5の緩衝液400μlにTZ-BN-NOTA溶液10μl（5μgの）を追加します。 </li><li>適切な放射化学ノートキーピングの利益のために、以下のプロトコル（3.4から3.8）でその後の工程の前と後の投与量キャリブレータを用いて試料中の放射能の量を測定し、記録します。これは放射化学的収率での正確な決定に役立ちます。 </li><li> TZ-BN-NOTA溶液に64のCuの2000μCiの（74 MBqの）を追加します。 注：典型的には、[64のCu]のCuCl 2を 0.1NのHClの小体積（&lt;30μlの）で供給されるので、この原液のほんの体積（&lt;10μl）を、放射標識反応のために必要とされる。 【64のCu]のCuCl 2株式の大きなボリュームが必要な場合は、放射標識反応は、全反応容積を増大は許容される。しかし、放射性標識反応液のpHを確保するために注意深く監視されるべきであるそれはpHが4.0を下回らないこと。 </li><li>ソリューションは、穏やかに撹拌しながら室温で10分間インキュベートすることを許可する。 </li><li>インキュベーションの10分後、逆相C 18 HPLCクロマトグラフィーを用いて生成物を精製する。保持時間は、明らかに、各研究室（ポンプ、カラム、チューブなど ）のHPLC機器設定に大きく依存している。 64のCu-Tz-の保持時間、分が使用されている15以上5のMeCN / H 2 O：95から5:95のMeCN / H 2 O（0.1％TFAの両方）の勾配場合は、例を提示する無料で、非複合体64 Cuが周りに2-4分で溶媒先端で溶出する一方BN-NOTAは約9.8分であるべきである。 </li><li>ロータリーエバポレーターを用いて、HPLCの溶離液を取り除く。 </li><li> 0.9％滅菌生理食塩水で64のCu-TZ-BN-NOTA製品を再溶解。 注：64のCuの12.7時間の物理的半減期を考えると、これは手続きで許容停止点ではありません。 64のCu-TZ-BN-NOTの合成を行う放射性リガンドの注射の直前に、ステップ4.5によってすぐにステップ3.7に従ってください。 </li></ol> 生体内 、プレターゲッティングPETイメージング4. 注：プロトコルセクション3のように、プロトコルのこのステップでは、放射能の取り扱いと操作を含む。これらの手順を実行する前に研究者は、自宅の機関の放射線安全課に相談してください。電離放射線への暴露を最小限に抑えるために可能なすべての手順を実行します。 <ol><li>雌の無胸腺ヌードマウス、皮下インプラント1×10 6 SW1222大腸癌細胞における、これらは（9-12日接種後）100〜150ミリメートル3異種移植片へと成長することができます。11 </li><li> 0.9％滅菌生理食塩水で0.5 mg / mlの濃度にプロトコル部2からhuA33-TCO溶液のアリコートを希釈する。 </li><li>異種移植片担持マウスの尾静脈にhuA33、TCO溶液200μl（100μgの）を注入する。 </li><li>マウスの腫瘍におけるhuA33-TCOの蓄積のための24時間を許可する。 </li><li> 0.9％滅菌生理食塩水で1.5 mCiの/ mlの濃度になるように64のCu-Tzを-Bnは、NOTAの放射性リガンドを希釈する。 </li><li>の尾静脈に（6.7 MBqで/ナノモルの比活性を仮定して、64のCu-TZ-BN-NOTAの1.6ナノモル; 11.1 MBqの300μCiの）64のCu-TZ-BN-NOTAの放射性リガンド溶液200μlを注入異種移植片担持マウス。 </li><li>酸素ガス混合物：所望の撮影時点（ 例えば、2、6、12、または24時間後に注射）で、2％イソフルランでマウスを麻酔。 </li><li>小動物PETスキャナーのベッドの上にマウスを置きます。酸素ガス混合物：1％イソフルランを使用して、スキャン中に麻酔を維持。スキャナベッド上に動物を配置する前に、つま先ピンチ方式を使用して麻酔を確認し、麻酔中の乾燥を防止するために、マウスの眼に獣医軟膏を適用する。 </li><li>静的介してマウス用PETデータを取得する350〜700 keVのエネルギーウィンドウと6ナノ秒の一致タイミングウィンドウを使用して2000万一致するイベントを最小限に抑えてスキャンします。画像の取得を完了した後、無人のマウスを残していないし、それが意識を取り戻したまで他のマウスとケージに入れないでください。 </li></ol>

<ol>
	<li>Wu, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antibodies+and+antimatter:+The+resurgence+of+immuno-PET.">Antibodies and antimatter: The resurgence of immuno-PET.</a> Journal of Nuclear Medicine. 50, 2-5 (2009).</li><li>Zeglis, B. M., Lewis, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+practical+guide+to+the+construction+of+radiometallated+bioconjugates+for+positron+emission+tomography.">A practical guide to the construction of radiometallated bioconjugates for positron emission tomography.</a> Dalton Transactions. 40, 6168-6195 (2011).</li><li>Hollander, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bispecific+antibodies+for+cancer+therapy.">Bispecific antibodies for cancer therapy.</a> Immunotherapy. 1, 211-222 (2009).</li><li>Liu, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tumor+pretargeting+in+mice+using+99mTc-labeled+morpholino,+a+DNA+analog.">Tumor pretargeting in mice using 99mTc-labeled morpholino, a DNA analog.</a> Journal of Nuclear Medicine. 43, 384-391 (2002).</li><li>Boerman, O. C., van Schaijk, F. G., Oyen, W. J. G., Corstens, F. H. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pretargeted+radioimmunotherapy+of+cancer:+Progress+step+by+step.">Pretargeted radioimmunotherapy of cancer: Progress step by step.</a> Journal of Nuclear Medicine. 44, 400-411 (2003).</li><li>Goldenberg, D. M., Sharkey, R. M., Paganelli, G., Barbet, J., Chatal, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antibody+pretargeting+advances+cancer+radioimmunodetection+and+radioimmunotherapy.">Antibody pretargeting advances cancer radioimmunodetection and radioimmunotherapy.</a> Journal of Clinical Oncology. 24, 823-834 (2006).</li><li>Sharkey, R. M., Chang, C. H., Rossi, E. A., McBride, W. J., Goldenberg, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pretargeting:+taking+an+alternate+route+for+localizing+radionuclides.">Pretargeting: taking an alternate route for localizing radionuclides.</a> Tumor Biology. 33, 591-600 (2012).</li><li>Sharkey, R. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improving+the+delivery+of+radionuclides+for+imaging+and+therapy+of+cancer+using+pretargeting+methods.">Improving the delivery of radionuclides for imaging and therapy of cancer using pretargeting methods.</a> Clinical Cancer Research. 11, 7109-7121 (2005).</li><li>Schultz, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+tetravalent+single-chain+antibody-streptavidin+fusion+protein+for+pretargeted+lymphoma+therapy.">A tetravalent single-chain antibody-streptavidin fusion protein for pretargeted lymphoma therapy.</a> Cancer Research. 60, 6663-6669 (2000).</li><li>Lewis, M. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+evaluation+of+pretargeted+64Cu+for+tumor+imaging+and+therapy.">In vivo evaluation of pretargeted 64Cu for tumor imaging and therapy.</a> Journal of Nuclear Medicine. 44, 1284-1292 (2003).</li><li>Zeglis, B. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+pretargeted+PET+imaging+strategy+based+on+bioorthgonal+Diels-Alder+click+chemistry.">A pretargeted PET imaging strategy based on bioorthgonal Diels-Alder click chemistry.</a> Journal of Nuclear Medicine. 54, 1389-1396 (2013).</li><li>Blackman, M. L., Royzen, M., Fox, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tetrazine+ligation:+fast+bioconjugation+based+on+inverse+electron+demand+Diels-Alder+reactivity.">Tetrazine ligation: fast bioconjugation based on inverse electron demand Diels-Alder reactivity.</a> Journal of the American Chemical Society. 130, 13518-13519 (2008).</li><li>Devaraj, N. K., Upadhyay, R., Hatin, J. B., Hilderbrand, S. A., Weissleder, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fast+and+sensitive+pretargeted+labeling+of+cancer+cells+through+a+tetrazine/trans-cyclooctene+cycloaddition.">Fast and sensitive pretargeted labeling of cancer cells through a tetrazine/trans-cyclooctene cycloaddition.</a> Angewandte Chemie-International Edition. 48, 7013-7016 (2009).</li><li>Devaraj, N. K., Weissleder, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biomedical+applications+of+tetrazine+cycloadditions.">Biomedical applications of tetrazine cycloadditions.</a> Accounts of Chemical Research. 44, 816-827 (2011).</li><li>Devaraj, N. K., Weissleder, R., Hilderbrand, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tetrazine-based+cycloadditions:+application+to+pretargeted+live+cell+imaging.">Tetrazine-based cycloadditions: application to pretargeted live cell imaging.</a> Bioconjugate Chemistry. 19, 2297-2299 (2008).</li><li>Keliher, E. J., Reiner, T., Turetsky, A., Hilderbrand, S., Weinberg, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-yielding,+two-step+18F+labeling+strategy+for+18F-PARP1+inhibitors.">High-yielding, two-step 18F labeling strategy for 18F-PARP1 inhibitors.</a> ChemMedChem. 6, 424-427 (2011).</li><li>Reiner, T., Earley, S., Turetsky, A., Weissleder, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bioorthogonal+small-molecule+ligands+for+PARP1+imaging+in+living+cells.">Bioorthogonal small-molecule ligands for PARP1 imaging in living cells.</a> ChemBioChem. 11, 2375-2377 (2010).</li><li>Reiner, T., Keliher, E. J., Earley, S., Marinelli, B., Weissleder, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+and+in+vivo+imaging+of+a+18F-labeled+PARP1+inhibitor+using+a+chemically+orthogonal+scavenger-assisted+high-performance+method.">Synthesis and in vivo imaging of a 18F-labeled PARP1 inhibitor using a chemically orthogonal scavenger-assisted high-performance method.</a> Angewandte Chemie International Edition. 50, 1922-1925 (2011).</li><li>Taylor, M. T., Blackman, M., Dmitrenko, O., Fox, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Design+and+synthesis+of+highly+reactive+dienophiles+for+the+tetrazine-trans-cyclooctene+ligation.">Design and synthesis of highly reactive dienophiles for the tetrazine-trans-cyclooctene ligation.</a> Journal of the American Chemical Society. 133, 9646-9649 (2011).</li><li>Selvaraj, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tetrazine-trans-cyclooctene+ligation+for+the+rapid+construction+of+integrin+alpha(v)beta(3)+targeted+PET+tracer+based+on+a+cyclic+RGD+peptide.">Tetrazine-trans-cyclooctene ligation for the rapid construction of integrin alpha(v)beta(3) targeted PET tracer based on a cyclic RGD peptide.</a> Bioorganic and Medicinal Chemistry Letters. 21 (3), 5011-5014 (2011).</li><li>Liu, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+18F+labeling+of+cysteine-containing+peptides+and+proteins+using+tetrazine-trans-cyclooctene+ligation.">Efficient 18F labeling of cysteine-containing peptides and proteins using tetrazine-trans-cyclooctene ligation.</a> Molecular Imaging. 12, 121-128 (2013).</li><li>Han, H. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+a+bioorthogonal+and+highly+efficient+conjugation+method+for+quantum+dots+using+tetrazine-norbornene+cycloaddition.">Development of a bioorthogonal and highly efficient conjugation method for quantum dots using tetrazine-norbornene cycloaddition.</a> Journal of the American Chemical Society. 132, 7838-7839 (2010).</li><li>Zeglis, B. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modular+strategy+for+the+construction+of+radiometalated+antibodies+for+positron+emission+tomography+based+on+inverse+electron+demand+Diels-Alder+click+chemistry.">Modular strategy for the construction of radiometalated antibodies for positron emission tomography based on inverse electron demand Diels-Alder click chemistry.</a> Bioconjugate Chemistry. 22, 2048-2059 (2011).</li><li>Zeng, D., Zeglis, B. M., Lewis, J. S., Anderson, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+growing+impact+of+bioorthogonal+click+chemistry+on+the+development+of+radiopharmaceuticals.">The growing impact of bioorthogonal click chemistry on the development of radiopharmaceuticals.</a> Journal of Nuclear Medicine. 54, 829-832 (2013).</li><li>Reiner, T., Zeglis, B. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+inverse+electron+demand+Diels-Alder+reaction+in+radiochemistry.">The inverse electron demand Diels-Alder reaction in radiochemistry.</a> Journal of Labeled Compounds and Radiopharmaceuticals. 57, 285-290 (2014).</li><li>Li, Z., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tetrazine-trans-cyclooctene+ligation+for+the+rapid+construction+of+18-F+labeled+probes.">Tetrazine-trans-cyclooctene ligation for the rapid construction of 18-F labeled probes.</a> Chemical Communications. 46, 8043-8045 (2010).</li><li>Karver, M. R., Weissleder, R., Hilderbrand, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+and+evaluation+of+a+series+of+1,2,4,5-tetrazines+for+bioorthogonal+conjugation.">Synthesis and evaluation of a series of 1,2,4,5-tetrazines for bioorthogonal conjugation.</a> Bioconjugate Chemistry. 22, 2263-2270 (2011).</li><li>Sletten, E. M., Bertozzi, C. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bioorthogonal+chemistry:+fishing+for+selectivity+in+a+sea+of+functionality.">Bioorthogonal chemistry: fishing for selectivity in a sea of functionality.</a> Angewandte Chemie International Edition. 48, 6973-6998 (2009).</li><li>Bosch, S. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+strained+alkynes+for+Cu-free+click+reaction+in+live+mice.">Evaluation of strained alkynes for Cu-free click reaction in live mice.</a> Nuclear Medicine and Biology. 40, 415-423 (2013).</li><li>Rossin, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+chemisry+for+pretargeted+tumor+imaging+in+live+mice.">In vivo chemisry for pretargeted tumor imaging in live mice.</a> Angewandte Chemie International Edition. 49, 3375-3378 (2010).</li><li>Ackerman, M. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A33+antigen+displays+persistent+surface+expression.">A33 antigen displays persistent surface expression.</a> Cancer Immunology and Immunotherapy. 57, 1017-1027 (2008).</li><li>Carrasquillo, J. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=124I-huA33+antibody+PET+of+colorectal+cancer.">124I-huA33 antibody PET of colorectal cancer.</a> Journal of Nuclear Medicine. 52, 1173-1180 (2011).</li><li>Sakamoto, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+phase+I+radioimmunolocalization+trial+of+humanized+monoclonal+antibody+huA33+in+patients+with+gastric+carcinoma.">A phase I radioimmunolocalization trial of humanized monoclonal antibody huA33 in patients with gastric carcinoma.</a> Cancer Science. 97, 1248-1254 (2006).</li><li>Rossin, R., Lappchen, R., vanden Bosch, S. M., LaForest, R., Robillard, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diels-Alder+reaction+for+tumor+pretargeting:+In+vivo+chemistry+can+boost+tumor+radiation+dose+compared+with+directly+labeled+antibody.">Diels-Alder reaction for tumor pretargeting: In vivo chemistry can boost tumor radiation dose compared with directly labeled antibody.</a> Journal of Nuclear Medicine. 54, 1989-1995 (2013).</li><li>Rossin, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Highly+reactive+trans-cyclooctene+tags+with+improved+stability+for+Diels-Alder+chemistry+in+living+systems.">Highly reactive trans-cyclooctene tags with improved stability for Diels-Alder chemistry in living systems.</a> Bioconjugate Chemistry. 34, 1210-1217 (2014).</li><li>Emmetiere, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=18F-labeled-bioorthogonal+liposomes+for+in+vivo+targeting.">18F-labeled-bioorthogonal liposomes for in vivo targeting.</a> Bioconjugate Chemistry. 24, 1784-1789 (2013).</li></ol>

The authors have nothing to disclose.

このプレターゲッティングPETイメージング戦略の主な利点は、直接標識された抗体によって生成バックグラウンド放射線量のほんの一部で標的対バックグラウンド画像コントラストを有する腫瘍の輪郭を描くことが可能であることである。例えば、ここに記載の結腸直腸癌のイメージングシステムにおいて、急性生体内分布実験からのデータは、直接標識された64のCu-NOTA-huA33 89</s...

最後の30年間で、陽電子放射断層撮影（PET）は、癌の診断と管理に不可欠な臨床ツールとなっている。抗体は、長い癌バイオマーカーに対するそれらの絶妙な親和性および特異性に起因する腫瘍への陽電子放出放射性同位元素の送達のための有望なベクターであると考えられている。抗体の1,2-しかしながら、比較的遅いインビボでの薬物動態は、複数日と放射性同位元素の使用を義務付け物理的半減期。この組み合わせは、患者の非標的器官、放射性免疫複合体を静脈内、したがって注入されるので、特定の臨床的意義のある重要な合併症に高い放射線量を得ることができる - 部分ボディCTスキャンとは異なり - 身体のあらゆる部分に吸収線量をもたらす、尋問組織の関係なく。 この問題を回避するためには、かなりの努力がdeveloに専念してきました同時に、それらの固有の薬物動態学的限界を幅木つつ抗体の有利な特性を活用し、放射性同位体と標的部分を切り離すPETイメージング戦略のpment。これらの戦略は-最も頻繁にプレターゲッティングまたは多段階のターゲティングと呼ばれる- 典型的には4つのステップを使用する：（1）抗原および放射性リガンドの両方に結合することができる抗体を投与する。 （2）標的組織及び血液からのそのクリアランスにおける抗体の蓄積。 （3）小分子、放射性リガンドを投与する。 （4）過剰な放射性リガンドの迅速なクリアランスによって。場合によっては3-8続い抗体に対する放射性リガンドのインビボでの連結は、追加のクリアリング剤は、任意の抗体の排泄を促進するために、手順2と3の間に注入されるそれは、腫瘍をバインドするためにまだあり、血液中に残っている。5 広義には、TWを話すプレターゲッティング戦略のO型は、文学の中で最も普及している。両方の前臨床モデルで成功を収めているが、それらはまた、それらの臨床適用を妨げている重要な制限を有する。最初の戦略は、ストレプトアビジン結合抗体およびビオチン修飾放射標識の間に高い親和性に依存しています。しかし、ストレプトアビジンで修飾された抗体の免疫原性は、翻訳に関して気になる問題があることが証明されている。 メタノシクロオクタ第二の戦略は、対照的に、癌の両方に結合するように遺伝子操作された二重特異性抗体を用いてバイオマーカー抗原と小分子、放射性標識ハプテン。3,11-14この後者のルートは確かに創造的である一方、その広範な適用は複雑さ、費用、およびシステムのモジュール性の欠如によって制限されている。 最近、我々は、逆電子需要ディールス - アルダーに基づくプレターゲッティングPET画像化方法論を開発し、公開された（Iトランス -cyclooctene（TCO）とテトラジン（Tzの間EDDA）付加環化反応; 図1）11反応自体は何十年も知られているがで示されるように、IEDDA化学は、クリック化学バイオコンジュゲーション技術として、近年、ルネッサンスを経験しているとりわけラルフ·ワスリーダー、ジョセフ·フォックス、そしてピーター·コンティのグループの魅力的な作品。12-15 IEDDAの環は、蛍光ペプチドでのイメージング、抗体、およびナノ粒子だけでなく、核画像を含め、設定の広い範囲で適用されている。批判- -バイオ直交27とクリックケミストリーの種類数ながら。放射性ハロゲンと放射性金属の両方で16-26ライゲーションは高い収穫、清潔、迅速な（K 1&gt;3万M -1秒-1）、選択され、 -銅触媒によるアジド - アルキン付加環、ストレイン·昇格アジド - アルキン付加環、及びシュタウディンガーLIG含む管理ポイント- 。それは生物全体でアプリケーションをプレターゲッティングに適しとてもよくIEDDA化学を行い、反応速度が速くとbioorthogonalityのユニークな組み合わせであるだけでなく、バイオ直交であるこれらの線に沿って28,29、それがあることを私たちの最近の報告に注意することが重要である研究所は、プレターゲッティングにIEDDA化学を適用することが第一ではなかった：IEDDAと予め標的イメージングの最初の報告は、 ら Rossin、の仕事から生じたと111 In標識テトラジンを採用したSPECTの方法論を特色にした30。。 我々は、上述のように、プレターゲッティング方法は、4つの非常に単純な手順（ 図2）を有している。手元プロトコルでは、64のCu-NOTA標識テトラジン放射性リガンド及びhuA33抗体のTCO変性共役を用いた結腸直腸癌のPET画像化のためのプレターゲッティング戦略を説明する。しかし、最終的にはこの方法論のモジュールは、そのGRの一つですトランス -cyclooctene部分としてeatest資産は、非内在化抗体に付加することができ、テトラジン、放射性レポーターの多種多様に取り付けることができる。

<table border="0" cellpadding="0" cellspacing="0" width="565">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;">Tetrazine NHS Ester</td>
			<td>Sigma-Aldrich</td>
			<td>764701</td>
			<td>Store at -80 &#176;C</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Trans-cyclooctene NHS Ester</td>
			<td>Sigma-Aldrich</td>
			<td>764523</td>
			<td>Store at -80 &#176;C</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">p-NH2-Bn-NOTA</td>
			<td>Macrocyclics</td>
			<td>B-601</td>
			<td>Store at -80 &#176;C</td>
		</tr>
	</tbody>
</table>

harnessing the bioorthogonal inverse electron demand diels-alder cycloaddition for pretargeted pet imaging

Due to their exquisite affinity and specificity, antibodies have become extremely promising vectors for the delivery of radioisotopes to cancer cells for PET imaging. However, the necessity of labeling antibodies with radionuclides with long physical half-lives often results in high background radiation dose rates to non-target tissues. In order to circumvent this issue, we have employed a pretargeted PET imaging strategy based on the inverse electron demand Diels-Alder cycloaddition reaction. The methodology decouples the antibody from the radioactivity and thus exploits the positive characteristics of antibodies, while eschewing their pharmacokinetic drawbacks. The system is composed of four steps: (1) the injection of a mAb-trans-cyclooctene (TCO) conjugate; (2) a localization time period during which the antibody accumulates in the tumor and clears from the blood; (3) the injection of the radiolabeled tetrazine; and (4) the in vivo click ligation of the components followed by the clearance of excess radioligand. In the example presented in the work at hand, a 64Cu-NOTA-labeled tetrazine radioligand and a trans-cyclooctene-conjugated humanized antibody (huA33) were successfully used to delineate SW1222 colorectal cancer tumors with high tumor-to-background contrast. Further, the pretargeting methodology produces high quality images at only a fraction of the radiation dose to non-target tissue created by radioimmunoconjugates directly labeled with 64Cu or 89Zr. Ultimately, the modularity of this protocol is one of its greatest assets, as the trans-cyclooctene moiety can be appended to any non-internalizing antibody, and the tetrazine can be attached to a wide variety of radioisotopes.

実験の最初の三つのステップ- TZ-BN-NOTA、huA33にTCOの結合の合成、およびTZ-BN-NOTAの放射性標識（ 図3、図4）を構築は-信頼性が高いです。上記の手順の場合には、Tzを-Bnは、NOTA構築物を高収率および高純度で合成した。 〜huA33抗体は4.2±0.6、TCO / mAbで変更された、とTZ-BN-NOTAは、&gt; 85％の減衰補正後の収量、および比活性&gt; 99％の放射化学的純度に精製された放射性リガンドを得る?...

Watch this Scientific Journal Video about Harnessing the Bioorthogonal Inverse Electron Demand Diels-Alder Cycloaddition for Pretargeted PET Imaging at JoVE.com

Harnessing the Bioorthogonal Inverse Electron Demand Diels-Alder Cycloaddition for Pretargeted PET Imaging

The bioorthogonal inverse electron demand Diels-Alder cycloaddition has been harnessed to create an effective and modular pretargeted PET imaging strategy for cancer. In this protocol, the steps of this methodology are described in the context of a model system employing the colorectal cancer targeted antibody huA33 and a 64Cu-labeled radioligand.

プレターゲッティングPETイメージング用バイオ直交逆電子需要ディールスアルダー環化を活用

Due to their exquisite affinity and specificity, antibodies have become extremely promising vectors for the delivery of radioisotopes to cancer cells for ...

harnessing-bioorthogonal-inverse-electron-demand-diels-alder

Research

JoVE Journal

Bioengineering

8.7K ビュー.  Memorial Sloan Kettering Cancer Center. The bioorthogonal inverse electron demand Diels-Alder cycloaddition has been harnessed to create an effective and modular pretargeted PET imaging strategy for cancer. In this protocol, the steps of this methodology are described in the context of a model system employing the colorectal cancer targeted antibody huA33 and a 64Cu-labeled radioligand. 

ビデオ: Harnessing the Bioorthogonal Inverse Electron Demand Diels-Alder Cycloaddition for Pretargeted PET Imaging

High-resolution Fiber-optic Microendoscopy for in situ Cellular Imaging

Many biological and clinical studies require the longitudinal study and analysis of morphology and function with cellular level resolution. Traditionally, multiple experiments are run in parallel, with individual samples removed from the study at sequential time points for evaluation by light microscopy. Several intravital techniques have been developed, with confocal, multiphoton, and second harmonic microscopy all demonstrating their ability to be used for imaging in situ 1. With these systems, however, the required infrastructure is complex and expensive, involving scanning laser systems and complex light sources. Here we present a protocol for the design and assembly of a high-resolution microendoscope which can be built in a day using off-the-shelf components for under US$5,000. The platform offers flexibility in terms of image resolution, field-of-view, and operating wavelength, and we describe how these parameters can be easily modified to meet the specific needs of the end user.
We and others have explored the use of the high-resolution microendoscope (HRME) in in vitro cell culture 2-5, in excised 6 and living animal tissues 2,5, and in human tissues in vivo 2,7. Users have reported the use of several different fluorescent contrast agents, including proflavine 2-4, benzoporphyrin-derivative monoacid ring A (BPD-MA) 5, and fluoroscein 6,7, all of which have received full, or investigational approval from the FDA for use in human subjects. High-resolution microendoscopy, in the form described here, may appeal to a wide range of researchers working in the basic and clinical sciences. The technique offers an effective and economical approach which complements traditional benchtop microscopy, by enabling the user to perform high-resolution, longitudinal imaging in situ.

High-resolution Fiber-optic Microendoscopy for in situ Cellular Imaging

In many biological and clinical situations it is advantageous to study cellular processes as they evolve in their native microenvironment. Here we describe the assembly and use of a low-cost fiber-optic microscope which can provide real time imaging in cell culture, animal studies, and clinical patient studies.

高分解能光ファイバMicroendoscopy用その場で細胞イメージング

Many biological and clinical studies require the longitudinal study and analysis of morphology and function with cellular level resolution.  ...

生物工学

Microfluidic-based Electrotaxis for On-demand Quantitative Analysis of Caenorhabditis elegans' Locomotion

The nematode Caenorhabditis elegans is a versatile model organism for biomedical research because of its conservation of disease-related genes and pathways as well as its ease of cultivation. Several C. elegans disease models have been reported, including neurodegenerative disorders such as Parkinson's disease (PD), which involves the degeneration of dopaminergic (DA) neurons 1. Both transgenes and neurotoxic chemicals have been used to induce DA neurodegeneration and consequent movement defects in worms, allowing for investigations into the basis of neurodegeneration and screens for neuroprotective genes and compounds 2,3.
Screens in lower eukaryotes like C. elegans provide an efficient and economical means to identify compounds and genes affecting neuronal signaling. Conventional screens are typically performed manually and scored by visual inspection; consequently, they are time-consuming and prone to human errors. Additionally, most focus on cellular level analysis while ignoring locomotion, which is an especially important parameter for movement disorders.
We have developed a novel microfluidic screening system (Figure 1) that controls and quantifies C. elegans' locomotion using electric field stimuli inside microchannels. We have shown that a Direct Current (DC) field can robustly induce on-demand locomotion towards the cathode ("electrotaxis") 4. Reversing the field's polarity causes the worm to quickly reverse its direction as well. We have also shown that defects in dopaminergic and other sensory neurons alter the swimming response 5. Therefore, abnormalities in neuronal signaling can be determined using locomotion as a read-out. The movement response can be accurately quantified using a range of parameters such as swimming speed, body bending frequency and reversal time.
Our work has revealed that the electrotactic response varies with age. Specifically, young adults respond to a lower range of electric fields and move faster compared to larvae 4. These findings led us to design a new microfluidic device to passively sort worms by age and phenotype 6.
We have also tested the response of worms to pulsed DC and Alternating Current (AC) electric fields. Pulsed DC fields of various duty cycles effectively generated electrotaxis in both C. elegans and its cousin C. briggsae 7. In another experiment, symmetrical AC fields with frequencies ranging from 1 Hz to 3 KHz immobilized worms inside the channel 8.
Implementation of the electric field in a microfluidic environment enables rapid and automated execution of the electrotaxis assay. This approach promises to facilitate high-throughput genetic and chemical screens for factors affecting neuronal function and viability.

Microfluidic-based Electrotaxis for On-demand Quantitative Analysis of Caenorhabditis elegans&#039; Locomotion

A semi-automated micro-electro-fluidic method to induce on-demand locomotion in Caenorhabditis elegans is described. This method is based on the neurophysiologic phenomenon of worms responding to mild electric fields (&#x201C;electrotaxis&#x201D;) inside microfluidic channels. Microfluidic electrotaxis serves as a rapid, sensitive, low-cost, and scalable technique to screen for factors affecting neuronal health.

のオンデマンド定量分析のためのマイクロ流体ベースの走電性<em&gt;線虫（Caenorhabditis elegans）</em&gt; &#39;ロコモーション

The nematode Caenorhabditis elegans is a versatile model organism for biomedical research because of its conservation of disease-related genes and ...

Creating Adhesive and Soluble Gradients for Imaging Cell Migration with Fluorescence Microscopy

Cells can sense and migrate towards higher concentrations of adhesive cues such as the glycoproteins of the extracellular matrix and soluble cues such as growth factors. Here, we outline a method to create opposing gradients of adhesive and soluble cues in a microfluidic chamber, which is compatible with live cell imaging. A copolymer of poly-L-lysine and polyethylene glycol (PLL-PEG) is employed to passivate glass coverslips and prevent non-specific adsorption of biomolecules and cells. Next, microcontact printing or dip pen lithography are used to create tracks of streptavidin on the passivated surfaces to serve as anchoring points for the biotinylated peptide arginine-glycine-aspartic acid (RGD) as the adhesive cue. A microfluidic device is placed onto the modified surface and used to create the gradient of adhesive cues (100% RGD to 0% RGD) on the streptavidin tracks. Finally, the same microfluidic device is used to create a gradient of a chemoattractant such as fetal bovine serum (FBS), as the soluble cue in the opposite direction of the gradient of adhesive cues.

A method for the assembly of adhesive and soluble gradients in a microscopy chamber for live cell migration studies is described. The engineered environment combines antifouling surfaces and adhesive tracks with solution gradients and therefore allows one to determine the relative importance of guidance cues.

蛍光顕微鏡を用いたイメージング細胞遊走用接着剤及び可溶性グラデーションを作成する

Cells can sense and migrate towards higher concentrations of adhesive cues such as the glycoproteins of the extracellular matrix and soluble cues such as ...

Fluorescence-quenching of a Liposomal-encapsulated Near-infrared Fluorophore as a Tool for In Vivo Optical Imaging

Optical imaging offers a wide range of diagnostic modalities and has attracted a lot of interest as a tool for biomedical imaging. Despite the enormous number of imaging techniques currently available and the progress in instrumentation, there is still a need for highly sensitive probes that are suitable for in vivo imaging. One typical problem of available preclinical fluorescent probes is their rapid clearance in vivo, which reduces their imaging sensitivity. To circumvent rapid clearance, increase number of dye molecules at the target site, and thereby reduce background autofluorescence, encapsulation of the near-infrared fluorescent dye, DY-676-COOH in liposomes and verification of its potential for in vivo imaging of inflammation was done. DY-676 is known for its ability to self-quench at high concentrations. We first determined the concentration suitable for self-quenching, and then encapsulated this quenching concentration into the aqueous interior of PEGylated liposomes. To substantiate the quenching and activation potential of the liposomes we use a harsh freezing method which leads to damage of liposomal membranes without affecting the encapsulated dye. The liposomes characterized by a high level of fluorescence quenching were termed Lip-Q. We show by experiments with different cell lines that uptake of Lip-Q is predominantly by phagocytosis which in turn enabled the characterization of its potential as a tool for in vivo imaging of inflammation in mice models. Furthermore, we use a zymosan-induced edema model in mice to substantiate the potential of Lip-Q in optical imaging of inflammation in vivo. Considering possible uptake due to inflammation-induced enhanced permeability and retention (EPR) effect, an always-on liposome formulation with low, non-quenched concentration of DY-676-COOH (termed Lip-dQ) and the free DY-676-COOH were compared with Lip-Q in animal trials.

Fluorescence-quenching of a Liposomal-encapsulated Near-infrared Fluorophore as a Tool for In Vivo Optical Imaging

The use of fluorophores for in vivo imaging can be greatly limited by opsonization, rapid clearance, low detection sensitivity and cytotoxic effects on the host. Encapsulation of fluorophores in liposomes by film hydration and extrusion leads to fluorescence quenching and protection which enables in vivo imaging with high detection sensitivity.

のためのツールと​​してのリポソームカプセル化された近赤外蛍光体の蛍光消光<em&gt;インビボ</em&gt;光学イメージング

Optical imaging offers a wide range of diagnostic modalities and has attracted a lot of interest as a tool for biomedical imaging. Despite the enormous ...

Rapid Scan Electron Paramagnetic Resonance Opens New Avenues for Imaging Physiologically Important Parameters In Vivo

We demonstrate a superior method of 2D spectral-spatial imaging of stable radical reporter molecules at 250 MHz using rapid-scan electron-paramagnetic-resonance (RS-EPR), which can provide quantitative information under in vivo conditions on oxygen concentration, pH, redox status and concentration of signaling molecules (i.e., OH&#8226;, NO&#8226;). The RS-EPR technique has a higher sensitivity, improved spatial resolution (1 mm), and shorter acquisition time in comparison to the standard continuous wave (CW) technique. A variety of phantom configurations have been tested, with spatial resolution varying from 1 to 6 mm, and spectral width of the reporter molecules ranging from 16 &#181;T (160 mG) to 5 mT (50 G). A cross-loop bimodal resonator decouples excitation and detection, reducing the noise, while the rapid scan effect allows more power to be input to the spin system before saturation, increasing the EPR signal. This leads to a substantially higher signal-to-noise ratio than in conventional CW EPR experiments.

Rapid Scan Electron Paramagnetic Resonance Opens New Avenues for Imaging Physiologically Important Parameters In Vivo

A new electron paramagnetic resonance (EPR) method, rapid scan EPR (RS-EPR), is demonstrated for 2D spectral spatial imaging which is superior to the traditional continuous wave (CW) technique and opens new venues for in vivo imaging. Results are demonstrated at 250 MHz, but the technique is applicable at any frequency.

高速走査電子常磁性共鳴イメージング生理学的に重要なパラメータのための新しい道を開きます。<em&gt;インビボ</em

We demonstrate a superior method of 2D spectral-spatial imaging of stable radical reporter molecules at 250 MHz using rapid-scan ...

Correlative Light Electron Microscopy (CLEM) for Tracking and Imaging Viral Protein Associated Structures in Cryo-immobilized Cells

Due to its high resolution, electron microscopy (EM) is an indispensable tool for virologists. However, one of the main difficulties when analyzing virus-infected or transfected cells via EM are the low efficiencies of infection or transfection, hindering the examination of these cells. In order to overcome this difficulty, light microscopy (LM) can be performed first to allocate the subpopulation of infected or transfected cells. Thus, taking advantage of the use of fluorescent proteins (FPs) fused to viral proteins, LM is used here to record the positions of the "positive-transfected" cells, expressing a FP and growing on a support with an alphanumeric pattern. Subsequently, cells are further processed for EM via high pressure freezing (HPF), freeze substitution (FS) and resin embedding. The ultra-rapid freezing step ensures excellent membrane preservation of the selected cells that can then be analyzed at the ultrastructural level by transmission electron microscopy (TEM). Here, a step-by-step correlative light electron microscopy (CLEM) workflow is provided, describing sample preparation, imaging and correlation in detail. The experimental design can be also applied to address many cell biology questions.

Correlative Light Electron Microscopy CLEM for Tracking and Imaging Viral Protein Associated Structures in Cryo-immobilized Cells

A correlative light electron microscopy (CLEM) method is applied to image virus-induced intracellular structures via electron microscopy (EM) in cells that are previously selected by light microscopy (LM). LM and EM are combined as a hybrid imaging approach to achieve an integrated view of virus-host interactions.

相関光電子顕微鏡 (クレム) 追跡のウイルス蛋白質のイメージング関連するクライオ固定化細胞の構造

Due to its high resolution, electron microscopy (EM) is an indispensable tool for virologists. However, one of the main difficulties when analyzing ...

Measuring the Spin-Lattice Relaxation Magnetic Field Dependence of Hyperpolarized [1-13C]pyruvate

The fundamental limit to in vivo imaging applications of hyperpolarized 13C-enriched compounds is their finite spin-lattice relaxation times. Various factors affect the relaxation rates, such as buffer composition, solution pH, temperature, and magnetic field. In this last regard, the spin-lattice relaxation time can be measured at clinical field strengths, but at lower fields, where these compounds are dispensed from the polarizer and transported to the MRI, the relaxation is even faster and difficult to measure. To have a better understanding of the amount of magnetization lost during transport, we used fast field-cycling relaxometry, with magnetic resonance detection of 13C nuclei at ~0.75 T, to measure the nuclear magnetic resonance dispersion of the spin-lattice relaxation time of hyperpolarized [1-13C]pyruvate. Dissolution dynamic nuclear polarization was used to produce hyperpolarized samples of pyruvate at a concentration of 80 mmol/L and physiological pH (~7.8). These solutions were rapidly transferred to a fast field-cycling relaxometer so that relaxation of the sample magnetization could be measured as a function of time using a calibrated small flip angle (3&#176;-5&#176;). To map the T1 dispersion of the C-1 of pyruvate, we recorded data for different relaxation fields ranging between 0.237 mT and 0.705 T. With this information, we determined an empirical equation to estimate the spin-lattice relaxation of the hyperpolarized substrate within the mentioned range of magnetic fields. These results can be used to predict the amount of magnetization lost during transport and to improve experimental designs to minimize signal loss.

Measuring the Spin-Lattice Relaxation Magnetic Field Dependence of Hyperpolarized [1-13C]pyruvate

We present a protocol to measure the magnetic field dependence of the spin-lattice relaxation time of 13C-enriched compounds, hyperpolarized by means of dynamic nuclear polarization, using fast field-cycled relaxometry. Specifically, we have demonstrated this with [1-13C]pyruvate, but the protocol could be extended to other hyperpolarized substrates.

過偏光のスピン格子緩和磁場依存性の測定[1-13C]ピルビン酸

The fundamental limit to in vivo imaging applications of hyperpolarized 13C-enriched compounds is their finite spin-lattice relaxation times. Various ...

Lipidico Injection Protocol for Serial Crystallography Measurements at the Australian Synchrotron

A facility for performing serial crystallography measurements has been developed at the Australian synchrotron. This facility incorporates a purpose built high viscous injector, Lipidico, as part of the macromolecular crystallography (MX2) beamline to measure large numbers of small crystals at room temperature. The goal of this technique is to enable crystals to be grown/transferred to&#160;glass syringes to be used directly in the injector for serial crystallography data collection. The advantages of this injector include the ability to respond rapidly&#160;to changes in the flow rate without interruption of the stream. Several limitations for this high viscosity injector (HVI) exist which include a restriction on the allowed sample viscosities to &#62;10 Pa.s. Stream stability can also potentially be an issue depending on the specific properties of the sample. A detailed protocol for how to set up samples and operate the injector for serial crystallography measurements at the Australian synchrotron is presented here. The method demonstrates preparation of the sample, including the transfer of lysozyme crystals into a high viscous media (silicone grease), and the operation of the injector for data collection at MX2.

The goal of this protocol is to demonstrate how to prepare serial crystallography samples for data collection on a high viscous injector, Lipidico, recently commissioned at the Australian synchrotron.

オーストラリアシンクロトロンにおける逐次結晶学測定用リピニコ注入プロトコル

A facility for performing serial crystallography measurements has been developed at the Australian synchrotron. This facility incorporates a purpose built ...

Blood Flow Imaging with Ultrafast Doppler

The pulsed-Doppler effect is the main technique used in clinical echography to assess blood flow. Applied with conventional focused ultrasound Doppler modes, it has several limits. Firstly, a finely tuned signal filtering operation is needed to distinguish blood flows from surrounding moving tissues. Secondly, the operator must choose between localizing the blood flows or quantifying them. In the last two decades, ultrasound imaging has undergone a paradigm shift with the emergence of ultrafast ultrasound using unfocused waves. In addition to a hundredfold increase in framerate (up to 10000 Hz), this new technique also breaks the conventional quantification/localization trade-off, offering a complete blood flow mapping of the field of view and a simultaneous access to fine velocities measurements at the single-pixel level (down to 50 &#181;m). This data continuity in both spatial and temporal dimensions strongly improves the tissue/blood filtering process, which results in an increase sensitivity to small blood flow velocities (down to 1 mm/s). In this method paper, we aim to introduce the concept of ultrafast Doppler as well as its main parameters. Firstly, we summarize the physical principles of unfocused wave imaging. Then, we present the Doppler signal processing main steps. Particularly, we explain the practical implementation of the critical tissue/blood flow separation algorithms and on the extraction of velocities from these filtered data. This theoretical description is supplemented by in vitro experiences. A tissue phantom embedding a canal with flowing blood-mimicking fluid is imaged with a research programmable ultrasound system. A blood flow image is obtained and the flow characteristics are displayed for several pixels in the canal. Finally, a review of in vivo applications is proposed, showing examples in several organs such as carotids, kidney, thyroid, brain and heart.

This protocol shows how to apply ultrafast ultrasound Doppler imaging to quantify blood flows. After a 1 s long acquisition, the experimenter has access to a movie of the full field of view with axial velocity values for each pixel every &#8776;0.3 ms (depending on the ultrasound time of flight).

超高速ドップラーによる血流イメージング

The pulsed-Doppler effect is the main technique used in clinical echography to assess blood flow. Applied with conventional focused ultrasound Doppler ...

Establishing an Octopus Ecosystem for Biomedical and Bioengineering Research

Many developments in biomedical research have been inspired by discovering anatomical and cellular mechanisms that support specific functions in different species. The octopus is one of these exceptional animals that has given scientists new insights into the fields of neuroscience, robotics, regenerative medicine, and prosthetics. Research with this species of cephalopods requires the set-up of complex facilities and intensive care for both the octopus and its ecosystem that is critical for the project&#39;s success. This system requires multiple mechanical and biological filtering systems to provide a safe and clean environment for the animal. Along with the control system, specialized routine maintenance and cleaning are required to effectively keep the facility operating long term. It is advised to provide an enriched environment to these intelligent animals by changing the tank&#39;s landscape, incorporating a variety of prey, and introducing challenging tasks for them to work through. Our results include MRI and a whole-body autofluorescence imaging as well as behavioral studies to better understand their nervous system. Octopuses possess unique physiology that can impact many areas of biomedical research. Providing them with a sustainable ecosystem is the first crucial step in uncovering their distinct capabilities.

Understanding the unique physiological and anatomical structures of octopuses can greatly impact biomedical research. This guide demonstrates how to set-up and maintain a marine environment to accommodate this species and includes state-of-the-art imaging and analytical approaches to visualize octopus' nervous system anatomy and function.

生物医学・バイオエンジニアリング研究のためのタコ生態系の確立

Many developments in biomedical research have been inspired by discovering anatomical and cellular mechanisms that support specific functions in different ...