KG는 RA 웰치 재단 보조금 P-1760에 의해 지원되었다, 수학 및 (KG에) 과학 교육의 TCU 앤드류 연구소, TCU 연구 및 창조 활동 그랜트 (KG에)와 (JHS에) TCU SERC을 부여합니다.

비오틴-FC 시스테인의 합성 1. (1) <ol><li> 고체상 방법은 1 수지 바인딩 생성한다. <ol><li> 융해 된 주사기에 비오틴로드 수지 (250 ㎎, 0.145 밀리몰)을 놓고 디메틸 포름 아미드 (5 ml)에 그리기와 20 분 동안 실험실 통에 주사기를 흔들어 수지를 팽창. 솔루션을 추방하고 한 번 더 붓기 디메틸 포름 아미드를 반복합니다. </li><li> 10-15 분간 진탕 하였다 주사기에 디메틸 포름 아미드 20 % 피 페리 딘 4-6를 가하여의 Fmoc- 보호기를 제거한다. 피 페리 딘 다른 4-6 ml의 탈 보호 과정을 반복한다. ~, 디클로로 메탄 (3X)를 5 ㎖ 각 메탄올 (1 : 1), 3X : 메탄올 : 디클로로 메탄 (1) 디메틸 포름 아미드 3 배의 순서, 3X 디메틸 포름 아미드 수지를 세척 하였다. 가열시 블루의 존재에 의해 성공적으로 탈 보호를 확인하기 위해 구슬의 작은 샘플링 (~ 10)에 닌히 드린 시험 (+)를 수행합니다. </li><li> 1&#39;-의 Fmoc- 아미노 페로센 -1- 카르 복실 산을 함유하는 용액을 섞어(203.3 ㎎, 0.4350 밀리몰), 1- 히드 록시 벤조 트리아 졸 수화물 (58.8 ㎎, 0.413 밀리몰), 디 이소 프로필 카르 보디이 미드 (0.0673 ㎖, 0.435 밀리몰), 디 이소 프로필 에틸 아민 (0.0757 ㎖, 0.435 mmol) 및 4 : 1 혼합물을 디클로로 메탄 및 디메틸 포름 아미드. 융해 된 주사기에이를 그리고 6 시간 동안 실험실 진탕 기에서 흔들어 부드럽게. 시린지로부터 용액을 배출하고 전술 한 바와 같이 세척 하였다. </li><li> 커플 링을 확인 상술 한 바와 같이 (-) 닌히 드린 시험을 수행합니다. 닌히 드린 테스트는 여전히 잔기를 함유하는 철의 부착으로부터 유도 비드의 오렌지 색상을 확인에도 불구하고 커플 링에 유용 할 수있다. </li><li> 이어서, 디메틸 포름 아미드 중 20 % 피 페리 딘의 첨가에 의해 및 Fmoc기를 제거하고 전술 한 바와 같이 세척 하였다. 닌히 드린 시험 (+)를 Fmoc 등의 제거를 확인하는 데 사용되어야한다. </li><li> (0.0673 mL로의 Fmoc-의 Cys (Trt가)로 이루어지는 용액 -OH (254.8 ㎎, 0.4350 밀리몰), 1- 히드 록시 벤조 트리아 졸 수화물 (58.8 ㎎, 0.4125 밀리몰), 디 이소 프로필 카르 보디이 미드를 준비 0.4350밀리몰), 디 이소 프로필 에틸 아민 (0.0757 ㎖, 0.4350 밀리몰)을 4 : 디클로로 메탄 및 디메틸 포름 아미드 1 혼합물. 이 시스테인 결합 칵테일을 융해 된 주사기를 추가하고 부드럽게 6 시간 동안 흔들어. 전술 한 프로토콜을 사용하여 세척 하였다. </li><li> 20 % 피 페리 딘으로 세정 성분 및 Fmoc 제거하여, (-) 닌히 드린 시험을 이용하여 결합하는 것을 확인. 닌히 드린 시험 (+)를 사용하여 아민 무료 터미널을 확인합니다. </li></ol></li><li> 수지 1 개열. <ol><li> , TFA의 용액 (9.45 ㎖), 물 (0.25 ㎖), 1,2- 에탄 디티 올 (0.25 ㎖) 및 트리 이소 프로필 실란 (0.1 ml)에 확인 주사기에 추가 4 시간 동안 가볍게 흔들어. </li><li> 에펜 도르프 튜브에서 얻어진 적갈색 용액 모아서 서서히 공기 스트림을 사용하여 TFA를 증발시켰다. </li><li> 찬 디 에틸 에테르를 추가 (~ 15 mL)을 에펜 도르프 튜브는 교반과 형성되는, 하나를 석출한다. 원심 분리를 통해 제품 (1g, 5 분)를 분리합니다. 티디 에틸 에테르 세척 (~ 60 ml의 합계)과 원심 분리기의 암탉 반복주기는 빨강 / 갈색 고체로 일을 얻었다. </li></ol></li></ol> 2. 특성과 1의 분석 <ol><li> 신원은 1 H (16 스캔)과 중 메탄올 (300 μL) 및 ESI-MS 분석 (13) C NMR (512 스캔)를 사용하여 그림 2의 연결 및 구성과 일치하는지 확인합니다. 다음과 같은 결과를 기대합니다 : 1 H NMR 스펙트럼 (CD 3 OD) δ / PPM : 1.407-1.684 (m, 6H), 2.245 (t, 2H), 2.665-3.150 (m, 12H), 4.015 (t, 1H), 4.104 (D, 2H ), 4.274 (Q, 1H), 4.426 (D, 2H), 4.479 (Q, 1H), 4.595 (t, 1H) 13 C NMR 스펙트럼 (CD 3 OD) δ / PPM : 24.644 (CH 2), 25.472 (CH 2), 28.051 (CH 2), 28.300 (CH 2), 35.474 (CH 2), 38.698 (CH 2), 39.241 (CH 2), 39.717 (CH 2), 55.340 / 55.538 (CP 링), 60.286 (CH), 61.964 (CH), 62.521 / 62.821 (CP 링), 66.038 / 66.170 (CP 링), 69.153 / 69.328 (CP 링), 71.468 / 71.593 (CP 링), 76.466 (CH), 171.770 (C = O), 175.361 (C = O). ESI-MS (m / Z)는 : 찾았 639.00 [1 + 나] +, 이론 : 639.1 [1 + 나 +와 HR-MS (m / z) : 찾았 617.2049 [1 + H] +, 이론 : 617.1622 [1 + H] +. </li><li> HPLC에게, 절연 1의 구성을 확인하는 원소 분석을 수행합니다. C8을 사용하여 수행 HPLC 크로마토 그램은 0.5 ㎖ / 분의 유속으로 100 % MeOH로 위상 반전 컬럼. 참고 : HPLC 유지 시간은 같다 : 3.198-4.674 분. </li></ol> 골드 표면에 1 항에 고정화 <ol><li> 컷 폴리머는 2 ~ 0.25 제곱에 금 슬라이드를 백업. </li><li> 1 (~ 1 ㎜)의 DI 워터 솔루션 (50) 비이커를 입력합니다. </li><li> 비커에 금 슬라이드를 추가하고 시계 유리 커버. 모든아야 유리 슬라이드을 교반없이 실온에서 O / N을 배양한다. </li><li> 용액으로부터 금 슬라이드를 제거하고 공기가 건조 할 수 있습니다. </li><li> 고정화되는 감시 한 주사 전자 현미경 (또는 등가)를 사용하여 전자 현미경 이미지를 스캔 구합니다. </li></ol>

The authors have nothing to disclose.

비대칭 페로센 유도체의 합성은 용액에 도전하고있다. 예를 들어, 용액은 목적하는 생성물 (20 % 이하)의 낮은 수율로 한 결과를 생성하기 위해 시도한다. 마찬가지로, 1&#39;- 아미노 페로센 카복실산 (산세 Fmoc 등) 및 결합 된 수지를 이용하는 비오틴 반응 Baristic 등에 의해보고 된 중합 생성물과 일치 불용성 생성물 결과. 최소한의 제품. (47)이 더 페로 복잡 및 그 ?...

바이오 센서는 선택적 분석 플랫폼으로 생체 분자 인식 기술을 채용하고 특이성, 속도 및 저가에 이용되는 소형 장치이다. 생체 분자의 검출을위한 전기 화학 바이오 센서는 그들의 단순성, 비용 효율성, 그리고 고감도로이 필드의 선두에있다. 이러한 센서의 1,3- 일반적인 해부학 관심 생물학적 마커에 특이적인 인식 분자 구비 전극 인 . 분자 인식하여 바이오 마커의 결합 단순한 측정에 의해 검출 될 수 전위 또는 전류의 로컬 변경을 초래한다. 효소에서 4-8 항체, 9-12 전체 세포, 13-16 수용체, 17 ~ 20 펩타이드 21-23과 DNA (24) 크게 더 큰 생물 분자에 초점을 맞추고있다 범위 수있는 인식 부분을 날짜합니다. 25 ~ 28 연구를 이 분야에서의 노력은 면역 센서 갔지에 주로 집중하고면역 글로불린은 산화 환원 활성 코어 고정화 (예 페로센 등) 및 관심있는 항체를 검출하는 데 사용되는 재. 이러한 연구는 항원 / 항체의 사용에서 발생하는 합병증에 따른 불량으로 인한 정밀도와 시간 소비 임상 적용에서 제외되었습니다. 1,3 성장주의는 생명의 작은 분자의 검출 (이하 1kg / 몰)에 초점을 맞추고있다 음식과 국가 안보 외에 환경 관심사. 바이오 센서 장치 (29)의 가장 잘 알려진 예는 포켓 사이즈 m에 연결된 전류계 스크린 인쇄 된 효소 전극이 셀프 테스트 포도당 모니터링이다. 이러한 시스템은 일반적으로 포도당 산화 반응에 의해 생성 된 전하의 총량은 시간의 기간에 걸쳐 측정되는 전기량 방법을 이용한다. 유가 장치, 휴대용 강력하고 있어야 큰에서 인구에 대한 손쉬운 사용하기 위해 핸드 헬드. 이러한 페로센 (ferrocene) 등의 산화 환원 태그 necessa 있습니다대부분의 바이오 마커는 본질적으로 전기 화학적 활성 아니기 때문에 공예는 용액에서 바이오 마커 또는 작은 분자의 전기 화학적 검출을 제공합니다. (30-38) 페로센은 전기 화학적 바이오 센서로의 통합을위한 훌륭한 선택이 전기 화학을위한 황금 표준 인 유기 금속 분자이다. 페로센 기반의 산화 환원 활성 종은 이미 그들의 작은 크기, 좋은 안정성, 편리 합성 액세스, 쉽게 화학적 변형, 상대적으로 친 유성 및 산화 환원 조정의 용이성에 상당한 관심을 얻고있다. 3,30-42 작은 분자가 페로센 코어를 기반으로 금속 이온과 작은 분자의 검출기로 광범위하게 사용되었다. 이러한 생체 분자 등의 큰 종을 대상으로 32-38,43 시스템은 전기 화학적 표면에 내장 된 페로센 유도체에 큰 항체 또는 면역 글로불린의 첨부 파일을 이용했다. 1,3,39 , 각각의 경우에 (44), 잠재력과 현재 intensi철 III / II의 Fe의 산화 환원 커플의 TY 따라서 분석 물 분자의 존재를 나타내는 새로운 분광 핸들을 생성 분자 결합에 변경되었다. 이러한 변화는 시클로 펜타 디에 닐 고리의 파이 - 시스템과 철 D 오비탈 사이에서 발생 광범위한 오버랩으로부터 발생한다. 파이 시스템이 변경되는 경우, 즉, 유도하거나, 다음 궤도 상호 작용이 것, 차례로, 변화를 반응. 이 철 코어에 영향을 미칠 것입니다 및 철 III / 철 II 커플의 잠재력의 변화로 관찰 할 수있다. 40,45,46 이러한 특성은 전기 화학적 면역 또는 바이오 센서의 정량 에이전트로 사용하기에 이러한 시스템이 매력. 바이오 센서 용량에 특이 페로센 함유 시스템을 생산하기 위해, 그것은 표적 분자에 특이적인 바이오 리셉터와 하나의 Cp 환을 수정하고 전기 판독 또는 ELEC에 분자 테더로서 다른 CP 링을 이용하는 것이 최적trode (그림 1). 이러한 비대칭 페로센 유도체의 합성 부반응 및 분자간 가교 상에 형성된 다이머 및 폴리머 종의 형성에 의해 도전. 47 그러나, 아미드 결합을 생성하는 커플 링 화학이 생물학적 성분 등을 포함 페로센의 간단한 유도체를 제공하기위한 가장 직접적인 경로이고 펩타이드 및 그 대사 산물로. 따라서, 제 펩티드 합성에 메리 필드 (Merrifield)에 의해 1950 년대에 개발 된 고상 기법 페로센을 함유하는 유기 금속 화합물에 적용될 수있다. 갖는다 직교 치환 1&#39;-의 Fmoc- 아미노 페로센 -1- 카르 복실 산 분자 수용체 부위 (비오틴), 전기 리드 (페로센) 및 고정화 링커 성분 (시스테인)를 포함 할 수 페로센 시스템의 사용을 통해 건설하고 여기에 자세히 설명되어. 이 바이오 접합체의 합성 금 표면에 고정화 증거로도 설명된다. 이 작업 represen비오틴, 페로센 및 금 표면에 고정화 아미노산으로 이루어지는 시스템의 제 프레젠테이션 TS.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Biotin Novatag Resin</td>
			<td>NovaBiochem</td>
			<td>8550510001</td>
			<td></td>
		</tr>
		<tr>
			<td>TORVIQ 10ML LUER LOCK FRITTED SYRINGE</td>
			<td>Fisher</td>
			<td>NC9299151</td>
			<td></td>
		</tr>
		<tr>
			<td>piperdine</td>
			<td>Acros</td>
			<td>P/3520/PB05</td>
			<td></td>
		</tr>
		<tr>
			<td>ninhydrin test</td>
			<td>Sigma-Aldrich</td>
			<td>60017-1ea</td>
			<td></td>
		</tr>
		<tr>
			<td>1&#8217;-Fmoc-amino-ferrocene-1-carboxylic acid</td>
			<td>Omm Scientific</td>
			<td>Special Order</td>
			<td></td>
		</tr>
		<tr>
			<td>1-&#8203;Hydroxybenzotriazole hydrate</td>
			<td>Sigma-Aldrich</td>
			<td>157260-25G</td>
			<td></td>
		</tr>
		<tr>
			<td>N,N&#8242;-Diisopropylcarbodiimide</td>
			<td>Sigma-Aldrich</td>
			<td>D125407-5G</td>
			<td></td>
		</tr>
		<tr>
			<td>N,N-&#8203;Diisopropylethylamine</td>
			<td>Sigma-Aldrich</td>
			<td>496219-100ML</td>
			<td></td>
		</tr>
		<tr>
			<td>Fmoc-Cys(Trt)-OH</td>
			<td>Novabiochem</td>
			<td>8520080025</td>
			<td></td>
		</tr>
		<tr>
			<td>trifluoroacetic acid</td>
			<td>Sigma-Aldrich</td>
			<td>T5408</td>
			<td></td>
		</tr>
		<tr>
			<td>1,2-ethanedithiol</td>
			<td>Sigma-Aldrich</td>
			<td>2930</td>
			<td></td>
		</tr>
		<tr>
			<td>triisopropyl silane</td>
			<td>Sigma-Aldrich</td>
			<td>233781</td>
			<td></td>
		</tr>
		<tr>
			<td>Eppendorf tubes (20 mL)</td>
			<td>any source</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>methanol</td>
			<td>any source</td>
			<td></td>
			<td>dry with molecular sieves prior to use &#38; store in 100 mL media bottle for easy usage.</td>
		</tr>
		<tr>
			<td>dichloromethane</td>
			<td>any source</td>
			<td></td>
			<td>dry with molecular sieves prior to use &#38; store in 100 mL media bottle for easy usage.</td>
		</tr>
		<tr>
			<td>dimethylformamide</td>
			<td>any source</td>
			<td></td>
			<td>dry with molecular sieves prior to use &#38; store in 100 mL media bottle for easy usage.</td>
		</tr>
		<tr>
			<td>centrifuge</td>
			<td>any source</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

synthetic methodology for asymmetric ferrocene derived bio-conjugate systems via solid phase resin-based methodology

조기 발견이 가장 질환의 성공적인 치료의 핵심이며, 많은 종류의 암의 진단 및 치료에 특히 필수적이다. 사용되는 가장 일반적인 기술은 자기 공명 영상 (MRI), 양전자 방출 지형도 (PET), 및 계산 된 지형 (CT)과 같은 양상을 이미징 및 질병의 물리적 구조를 이해하는데 최적이지만 회만 매 4로 할 수 있습니다 조영제 및 전체 비용의 사용으로 인해 육주. 마음, 치료 프로토콜을 혁명 것, 질병 및 / 또는 임상의 사무실에서 치료 효능의 무대를 평가하고 적절한시기에 이렇게 바이오 센서 등의 기술, &quot;관리의 포인트&quot;의 개발. 1과에두고 생물학적으로 중요한 분자 (2)의 검출에 페로센 기반 바이오 센서를 탐색하는 수단은, 본원에 기재된 방법은 페로센 비오틴 바이오 컨쥬 게이트를 제조하기 위해 개발되었다. 이 보고서는 금 표면에 고정화 될 수 비오틴 - 페로센 시스테인 시스템에 초점을 맞출 것이다.

(1)의 수지 결합 된 형태는도 2에 도시되어있다. 페로센 성분의 공유 결합은 철분 흡수 반대로 연속 세정하고 영구적 인 착체를 함유하는 고정화 된 철 나타내는 수지 비드에 오렌지 색조를 일으킨다 수지 입자의 PEG 성분. 하나의 수지 - 유리 형태는 수지 비드에 색상이 동일하다. 수지 구슬에서 화합물의 제거 후, ​​방법에 의한 순도와 수율 (68 %)는 일반적?...

Watch this Scientific Journal Video about Synthetic Methodology for Asymmetric Ferrocene Derived Bio-conjugate Systems via Solid Phase Resin-based Methodology at JoVE.com

Synthetic Methodology for Asymmetric Ferrocene Derived Bio-conjugate Systems via Solid Phase Resin-based Methodology

The synthesis of asymmetric species of ferrocene is challenging using solution techniques. This report focuses on the methods carried out to produce a ferrocene-biotin bioconjugate using facile and clean reactions accomplished via solid-phase synthesis. Incorporation of a thiolate moiety is shown to impart the ability for immobilization on gold surfaces.

고상 수지 기반의 방법론을 통해 비대칭 페로센 유래 바이오 복합체 시스템 용 합성 방법론

Early detection is a key to successful treatment of most diseases, and is particularly imperative for the diagnosis and treatment of many types of cancer. ...

synthetic-methodology-for-asymmetric-ferrocene-derived-bio-conjugate

Research

JoVE Journal

Chemistry

9.6K 조회수.  Texas Christian University. The synthesis of asymmetric species of ferrocene is challenging using solution techniques. This report focuses on the methods carried out to produce a ferrocene-biotin bioconjugate using facile and clean reactions accomplished via solid-phase synthesis. Incorporation of a thiolate moiety is shown to impart the ability for immobilization on gold surfaces.

비디오: Synthetic Methodology for Asymmetric Ferrocene Derived Bio-conjugate Systems via Solid Phase Resin-based Methodology

High-pressure Sapphire Cell for Phase Equilibria Measurements of CO2/Organic/Water Systems

The high pressure sapphire cell apparatus was constructed to visually determine the composition of multiphase systems without physical sampling. Specifically, the sapphire cell enables visual data collection from multiple loadings to solve a set of material balances to precisely determine phase composition. Ternary phase diagrams can then be established to determine the proportion of each component in each phase at a given condition. In principle, any ternary system can be studied although ternary systems (gas-liquid-liquid) are the specific examples discussed herein. For instance, the ternary THF-Water-CO2 system was studied at 25 and 40&#160;&#176;C and is described herein. Of key importance, this technique does not require sampling. Circumventing the possible disturbance of the system equilibrium upon sampling, inherent measurement errors, and technical difficulties of physically sampling under pressure is a significant benefit of this technique. Perhaps as important, the sapphire cell also enables the direct visual observation of the phase behavior. In fact, as the CO2 pressure is increased, the homogeneous THF-Water solution phase splits at about 2 MPa. With this technique, it was possible to easily and clearly observe the cloud point and determine the composition of the newly formed phases as a function of pressure.
The data acquired with the sapphire cell technique can be used for many applications. In our case, we measured swelling and composition for tunable solvents, like gas-expanded liquids, gas-expanded ionic liquids and Organic Aqueous Tunable Systems (OATS)1-4. For the latest system, OATS, the high-pressure sapphire cell enabled the study of (1) phase behavior as a function of pressure and temperature, (2) composition of each phase (gas-liquid-liquid) as a function of pressure and temperature and (3) catalyst partitioning in the two liquid phases as a function of pressure and composition. Finally, the sapphire cell is an especially effective tool to gather accurate and reproducible measurements in a timely fashion.

High-pressure Sapphire Cell for Phase Equilibria Measurements of CO2/Organic/Water Systems

The high pressure sapphire cell apparatus is a unique tool to study, without sampling, phase behavior under a wide range of pressures. Using a cathetometer, very precise volume measurements can be recorded to measure liquid expansion and phase composition. Thus, this synthetic method enables the study of (1) phase equilibria of multi-component mixtures and (2) the partition behavior of catalyst or model compounds as a function of pressure.

CO의 상 평형 측정을위한 고압 사파이어 셀<sub&gt; 2</sub&gt; / 유기농 / 물 시스템

The high pressure sapphire cell apparatus was constructed to visually determine the composition of multiphase systems without physical sampling. ...

연구

화학

Stabilizing Hepatocellular Phenotype Using Optimized Synthetic Surfaces

Currently, one of the major limitations in cell biology is maintaining differentiated cell phenotype. Biological matrices are commonly used for culturing and maintaining primary and pluripotent stem cell derived hepatocytes. While biological matrices are useful, they permit short term culture of hepatocytes, limiting their widespread application. We have attempted to overcome the limitations using a synthetic polymer coating. Polymers represent one of the broadest classes of biomaterials and possess a wide range of mechanical, physical and chemical properties, which can be fine-tuned for purpose. Importantly, such materials can be scaled to quality assured standards and display batch-to-batch consistency. This is essential if cells are to be expanded for high through-put screening in the pharmaceutical testing industry or for cellular based therapy. Polyurethanes (PUs) are one group of materials that have shown promise in cell culture. Our recent progress in optimizing a polyurethane coated surface, for long-term culture of human hepatocytes displaying stable phenotype, is presented and discussed.

This article will focus on developing polymer coated surfaces for long-term, stable culture of stem cell derived human hepatocytes.

최적화 된 합성 표면을 간세포 표현형 사용 안정화

Currently, one of the major limitations in cell biology is maintaining differentiated cell phenotype. Biological matrices are commonly used for culturing ...

X-ray Powder Diffraction in Conservation Science: Towards Routine Crystal Structure Determination of Corrosion Products on Heritage Art Objects

The crystal structure determination and refinement process of corrosion products on historic art objects using laboratory high-resolution X-ray powder diffraction (XRPD) is presented in detail via two case studies.
The first material under investigation was sodium copper formate hydroxide oxide hydrate, Cu4Na4O(HCOO)8(OH)2&#8729;4H2O (sample 1) which forms on soda glass/copper alloy composite historic objects (e.g., enamels) in museum collections, exposed to formaldehyde and formic acid emitted from wooden storage cabinets, adhesives, etc. This degradation phenomenon has recently been characterized as &#34;glass induced metal corrosion&#34;.
For the second case study, thecotrichite, Ca3(CH3COO)3Cl(NO3)2&#8729;6H2O (sample 2), was chosen, which is an efflorescent salt forming needlelike crystallites on tiles and limestone objects which are stored in wooden cabinets and display cases. In this case, the wood acts as source for acetic acid which reacts with soluble chloride and nitrate salts from the artifact or its environment.
The knowledge of the geometrical structure helps conservation science to better understand production and decay reactions and to allow for full quantitative analysis in the frequent case of mixtures.

Modern high resolution X-ray powder diffraction (XRPD) in the laboratory is used as an efficient tool to determine crystal structures of long-known corrosion products on historic objects.

보존 과학의 X 선 분말 회절 : 문화 예술에 부식 제품의 일상적인 결정 구조 결정을 향해

The crystal structure determination and refinement process of corrosion products on historic art objects using laboratory high-resolution X-ray powder ...

Measurement of Particle Size Distribution in Turbid Solutions by Dynamic Light Scattering Microscopy

A protocol for measuring polydispersity of concentrated polymer solutions using dynamic light scattering is described. Dynamic light scattering is a technique used to measure the size distribution of polymer solutions or colloidal particles. Although this technique is widely used for the assessment of polymer solutions, it is difficult to measure the particle size in concentrated solutions due to the multiple scattering effect or strong light absorption. Therefore, the concentrated solutions should be diluted before measurement. Implementation of the confocal optical component in a dynamic light scattering microscope1 helps to overcome this barrier. Using such a microscopic system, both transparent and turbid systems can be analyzed under the same experimental setup without a dilution. As a representative example, a size distribution measurement of a temperature-responsive polymer solution was performed. The sizes of the polymer chains in an aqueous solution were several tens of nanometers at a temperature below the lower critical solution temperature (LCST). In contrast, the sizes increased to more than 1.0 &#181;m when above the LCST. This result is consistent with the observation that the solution turned turbid above the LCST.

A protocol for the direct measurement of particle size distribution in concentrated solutions using dynamic light scattering microscopy is presented.

A protocol for measuring polydispersity of concentrated polymer solutions using dynamic light scattering is described. Dynamic light scattering is a ...

Integration of Miniaturized Solid Phase Extraction and LC-MS/MS Detection of 3-Nitrotyrosine in Human Urine for Clinical Applications

Free 3-nitrotyrosine (3-NT) has been extensively used as a possible biomarker for oxidative stress. Increased levels of 3-NT have been reported in a wide variety of pathological conditions. However, existing methods lack the sufficient sensitivity and/or specificity necessary to measure the low endogenous level of 3-NT reliably and are too cumbersome for clinical applications. Hence, analytical improvement is urgently needed to accurately quantify the levels of 3-NT and verify the role of 3-NT in pathological conditions. This protocol presents the development of a novel liquid chromatography tandem mass spectrometry (LC-MS/MS) detection combined with a miniaturized solid phase extraction (SPE) for the rapid and accurate measurement of 3-NT in human urine as a non-invasive biomarker for oxidative stress. SPE using a 96-well plate markedly simplified the process by combining sample cleanup and analyte enrichment without tedious derivatization and evaporation steps, reducing solvent consumption, waste disposal, risk of contamination and overall processing time. The employment of 25 mM ammonium acetate (NH4OAc) at pH 9 as the SPE elution solution substantially enhanced the selectivity. Mass spectrometry signal response was improved through adjustment of the multiple reaction monitoring (MRM) transitions. Use of 0.01% HCOOH as additive on a pentafluorophenyl (PFP) column (150 mm x 2.1 mm, 3 &#181;m) improved signal response another 2.5-fold and shortened the overall run time to 7 min. A lower limit of quantitation (LLOQ) of 10 pg/mL (0.044 nM) was achieved, representing a significant sensitivity improvement over the reported assays. This simplified, rapid, selective and sensitive method allows two plates of urine samples (n = 192) to be processed in a 24 h time-period. Considering the markedly improved analytical performance, and non-invasive and inexpensive urine sampling, the proposed assay is beneficial for pre-clinical and clinical studies.

A selective and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method coupled with an efficient solid phase extraction on a mixed-mode cation-exchange (MCX) 96-well microplate was developed for the measurement of free 3-nitrotyrosine (3-NT) in human urine with high throughput, which is suitable for clinical applications.

임상 응용을위한 인간의 소변에서 3- 니트로 타이로신의 소형 고체 상 추출 및 LC-MS / MS 검출의 통합

Free 3-nitrotyrosine (3-NT) has been extensively used as a possible biomarker for oxidative stress. Increased levels of 3-NT have been reported in a wide ...

Application and Methodology of the Non-destructive 19F Time-domain NMR Technique to Measure the Content in Fluorine-containing Drug Products

Here, we describe a protocol developed by our group that uses low-field fluorine-19 (19F) time-domain (TD) nuclear magnetic resonance (NMR) to measure the average content of fluorinated drugs in their formulated drug product forms: tablets or capsules. This method is specific to fluorinated drugs because it detects only the content of fluorine, avoiding interference from the excipients that lack fluorine. The advantages of measuring the active content of fluorinated drugs using low-field 19F TD-NMR versus high-field 19F solid-state (SS) NMR are the simplicity of the method; the low cost; and the non-destructive nature of the technique, with all samples recoverable in intact forms (e.g., powders, tablets, and capsules), making this technique affordable for any laboratory.
We have tested the method with three fluorinated drug products available on the market - cinacalcet, lansoprazole, and ciprofloxacin - with doses ranging from 15 to 500 mg. The results of the analyses, measured by low-field 19F TD-NMR, supported the reported label claims for the average drug content.
Based on the simplicity and reproducibility of the analysis, we envision this methodology being implemented in any laboratory, including manufacturing plants, as a process analytical technology (PAT) tool in the pharmaceutical industry.

Application and Methodology of the Non-destructive 19F Time-domain NMR Technique to Measure the Content in Fluorine-containing Drug Products

A simple and non-destructive technique that measures the average content of drug substances in formulated drug products containing fluorine using low-field fluorine-19 (19F) time-domain (TD) nuclear magnetic resonance (NMR) is presented here. The technique can be applied to the development and manufacturing of drugs in the pharmaceutical industry.

응용 프로그램 및 비 파괴적인 19F 시간 영역 NMR 기법의 방법론 포함 하는 불 소 약 제품에 콘텐츠를 측정 하

Here, we describe a protocol developed by our group that uses low-field fluorine-19 (19F) time-domain (TD) nuclear magnetic resonance (NMR) to measure the ...

Phase Behavior of Charged Vesicles Under Symmetric and Asymmetric Solution Conditions Monitored with Fluorescence Microscopy

Phase-separated giant unilamellar vesicles (GUVs) exhibiting coexisting liquid-ordered and liquid-disordered domains are a common biophysical tool to investigate the lipid raft hypothesis. Numerous studies, however, neglect the impact of physiological solution conditions. On that account, the current work presents the effect of high-salinity buffer and trans-membrane solution asymmetry on liquid-liquid phase separation in charged GUVs grown from dioleylphosphatidylglycerol, egg sphingomyelin, and cholesterol. The effects were studied under isothermal and varying temperature conditions.
We describe equipment and experimental strategies applicable for monitoring the stability of coexisting liquid domains in charged vesicles under symmetric and asymmetric high-salinity solution conditions. This includes an approach to prepare charged multicomponent GUVs in high-salinity buffer at high temperatures. The protocol entails the option to perform a partial exchange of the external solution by a simple dilution step while minimizing the vesicle dilution. An alternative approach is presented utilizing a microfluidic device that allows for a complete external solution exchange. The solution effects on phase separation were also studied under varying temperatures. To this end, we present the basic design and utility of an in-house built temperature control chamber. Furthermore, we reflect on the assessment of the GUV phase state, pitfalls associated with it and how to circumvent them.

Experiments on phase separated giant unilamellar vesicles (GUVs) frequently neglect physiological solution conditions. This work presents approaches to study the effect of high-salinity buffer on liquid-liquid phase separation in charged multicomponent GUVs as a function of trans-membrane solution asymmetry and temperature.

형광 현미경 검사 법으로 모니터링 하는 대칭 및 비대칭 솔루션 조건에서 충전된 Vesicles의 위상 동작

Phase-separated giant unilamellar vesicles (GUVs) exhibiting coexisting liquid-ordered and liquid-disordered domains are a common biophysical tool to ...

Protocol for the Solid-phase Synthesis of Oligomers of RNA Containing a 2'-O-thiophenylmethyl Modification and Characterization via Circular Dichroism

Solid-phase synthesis has been used to obtain canonical and modified polymers of nucleic acids, specifically of DNA or RNA, which has made it a popular methodology for applications in various fields and for different research purposes. The procedure described herein focuses on the synthesis, purification, and characterization of dodecamers of RNA 5&#39;-[CUA CGG AAU CAU]-3&#39; containing zero, one, or two modifications located at the C2&#39;-O-position. The probes are based on 2-thiophenylmethyl groups, incorporated into RNA nucleotides via standard organic synthesis and introduced into the corresponding oligonucleotides via their respective phosphoramidites. This report makes use of phosphoramidite chemistry via the four canonical nucleobases (Uridine (U), Cytosine (C), Guanosine (G), Adenosine (A)), as well as 2-thiophenylmethyl functionalized nucleotides modified at the 2&#39;-O-position; however, the methodology is amenable for a large variety of modifications that have been developed over the years. The oligonucleotides were synthesized on a controlled-pore glass (CPG) support followed by cleavage from the resin and deprotection under standard conditions, i.e., a mixture of ammonia and methylamine (AMA) followed by hydrogen fluoride/triethylamine/N-methylpyrrolidinone. The corresponding oligonucleotides were purified via polyacrylamide electrophoresis (20% denaturing) followed by elution, desalting, and isolation via reversed-phase chromatography (Sep-pak, C18-column). Quantification and structural parameters were assessed via ultraviolet-visible (UV-vis) and circular dichroism (CD) photometric analysis, respectively. This report aims to serve as a resource and guide for beginner and expert researchers interested in embarking in this field. It is expected to serve as a work-in-progress as new technologies and methodologies are developed. The description of the methodologies and techniques within this document correspond to a DNA/RNA synthesizer (refurbished and purchased in 2013) that uses phosphoramidite chemistry.

Protocol for the Solid-phase Synthesis of Oligomers of RNA Containing a 2&#039;-O-thiophenylmethyl Modification and Characterization via Circular Dichroism

This article provides a detailed procedure on the solid-phase synthesis, purification, and characterization of dodecamers of RNA modified at the C2&#39;-O-position. UV-vis and circular dichroism photometric analyses are used to quantify and characterize structural aspects, i.e., single-strands or double-strands.

2&#39;- 포스 핀 올리고 뉴클레오타이드를 함유하는 올리고머의 고상 합성을위한 프로토콜<em&gt; O</em&gt; 원형 이색 성을 통한 - 티오 페닐 메틸 변형 및 특성 분석

Solid-phase synthesis has been used to obtain canonical and modified polymers of nucleic acids, specifically of DNA or RNA, which has made it a popular ...

Characterization of Synthetic Polymers via Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI-TOF) Mass Spectrometry

There are many techniques that can be employed in the characterization of synthetic homopolymers, but few provide as useful of information for end group analysis as matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS). This tutorial demonstrates methods for optimization of the sample preparation, spectral acquisition, and data analysis of synthetic polymers using MALDI-TOF MS. Critical parameters during sample preparation include the selection of the matrix, identification of an appropriate cationization salt, and tuning the relative proportions of the matrix, cation, and analyte. The acquisition parameters, such as mode (linear or reflector), polarization (positive or negative), acceleration voltage, and delay time, are also important. Given some knowledge of the chemistry involved to synthesize the polymer and optimizing both the data acquisition parameters and the sample preparation conditions, spectra should be obtained with sufficient resolution and mass accuracy to enable the unambiguous determination of the end groups of most homopolymers (masses below 10,000) in addition to the repeat unit mass and the overall molecular weight distribution. Though demonstrated on a limited set of polymers, these general techniques are applicable to a much wider range of synthetic polymers for determining mass distributions, though end group determination is only possible for homopolymers with narrow dispersity.

Characterization of Synthetic Polymers via Matrix Assisted Laser Desorption Ionization Time of Flight MALDI-TOF Mass Spectrometry

A protocol for the matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) characterization of synthetic polymers is described including the optimization of sample preparation, spectral acquisition, and data analysis.

매트릭스를 통해 합성 고분자의 특성화 지원 레이저 탈 착 이온화 시간의 비행 (TOF MALDI) 질량 분석

There are many techniques that can be employed in the characterization of synthetic homopolymers, but few provide as useful of information for end group ...

Solid-phase Synthesis of [4.4] Spirocyclic Oximes

A convenient synthetic route for spirocyclic heterocycles is well sought after due to the molecule&#39;s potential use in biological systems. By means of solid-phase synthesis, regenerating Michael (REM) linker strategies, and 1,3-dipolar cycloaddition, a library of structurally similar heterocycles, both with and without a spirocyclic center, can be constructed. The main advantages of the solid-support synthesis are as follows: first, each reaction step can be driven to completion using a large excess of reagents resulting in high yields; next, the use of commercially available starting materials and reagents keep the costs low; finally, the reaction steps are easy to purify via simple filtration. The REM linker strategy is attractive because of its recyclability and traceless nature. Once a reaction scheme is completed, the linker can be reused multiple times. In a typical solid-phase synthesis, the product contains either a part of or the whole linker, which can prove undesirable. The REM linker is &#34;traceless&#34; and the point of attachment between the product and the polymer is indistinguishable. The high diastereoselectivity of the intramolecular 1,3-dipolar cycloaddition is well documented. Limited by the insolubility of the solid support, the reaction progression can only be monitored by a change in the functional groups (if any) via infrared (IR) spectroscopy. Thus, the structural identification of intermediates cannot be characterized by conventional nuclear magnetic resonance (NMR) spectroscopy. Other limitations to this method stem from the compatibilities of the polymer/linker to the desired chemical reaction scheme. Herein we report a protocol that allows for the convenient production of spirocyclic heterocycles that, with simple modifications, can be automated with high-throughput techniques.

Here we present a protocol to demonstrate an efficient method for the synthesis of spirocyclic heterocycles. The five-step process utilizes solid-phase synthesis and regenerating Michael linker strategies. Generally difficult to synthesize, we present a customizable method for the synthesis of spirocyclic molecules otherwise inaccessible to other modern approaches.

[4.4] Spirocyclic Oximes의 고체 상 합성

A convenient synthetic route for spirocyclic heterocycles is well sought after due to the molecule&#39;s potential use in biological systems. By means of ...