This work is supported by NIH R00 HD032636.

1. Staining with the First Antibody
<ol>
	<li>Dewax and rehydrate FFPE slides with 5 min allotted to each of the following steps: xylene or equivalent reagents 3x, 100% ethanol 2x, 95% ethanol 1x, 70% ethanol 1x, 50% ethanol 1x, and distilled water 2x. 
	NOTE: Slides should remain moist starting from this rehydration step until mounting in the final step.</li>
	<li>For optional antigen retrieval, place the slides in 275 mL of boiling sodium citrate solution (10 mM, pH = 6.0) for 8 min. To keep the solution boiling, place the slides flat on the bottom of a 14 x 9.5 x 9 cm3 (W x L x H) pipette tip box with a lid and microwave the solution on 70% power in a 700 W microwave oven for 8 min. Then remove the pipette tip box from the microwave oven, open the lid, and let the solution cool down at room temperature (RT) for at least 20 min.</li>
	<li>Transfer the slides into a Coplin jar containing PBST (phosphate-buffered saline with 0.1% polysorbate 20/80). Wash with PBST for 5 min 3x. If not immediately moving to the next step, store the slides at this step with PBST in a Coplin jar at RT for a few hours or at 4 &#176;C for 1-2 days if not immediately moving to the next step.</li>
	<li>To prepare the blocking solution use the normal serum of the secondary antibody&#39;s host species as the blocking reagent. Other commercial blocking reagents may also be used. If using normal serum employed for the study presented in this study, add 100 &#181;L of normal donkey serum to 4.9 mL of PBST. The blocking solution can be stored at 4 &#176;C for up to 3 days.</li>
	<li>For blocking, shake off the PBST from the slides and quickly cover them with sufficient blocking solution. Incubate the slides at RT in a humidified chamber for 30 min.</li>
	<li>Prepare the primary antibody solution (500 &#181;L for two slides) using the blocking solution to dilute the primary antibody to the desired concentration. The solution should be stored on ice until use.
	<ol>
		<li>For 3&#946;HSD, add 2 &#181;L of 3&#946;HSD into 498 &#181;L of blocking solution.</li>
		<li>For TH, add 0.5 &#181;L of TH antibody into 499 &#181;L of blocking solution.</li>
		<li>For &#946;-catenin, add 1 &#181;L of &#946;-catenin antibody into 499 &#181;L of blocking solution.</li>
		<li>For 20&#945;HSD, add 1 &#181;L of 20&#945;HSD antibody into 499 &#181;L of blocking solution.</li>
		<li>For CYP2F2, add 2 &#181;L of CYP2F2 antibody into 498 &#181;L of blocking solution.</li>
	</ol>
	</li>
	<li>Incubate with the primary antibody by shaking off the blocking solution from the slides, and quickly covering them with sufficient primary antibody solution. Incubate the slides in a humidified chamber overnight at 4 &#176;C. During incubation the slides may be covered by a small piece of paraffin film to prevent drying out.</li>
	<li>The next morning wash the slides with PBST for 5 min 3x.</li>
	<li>Prepare the secondary antibody solution (500 &#181;L for two slides) using the blocking solution to dilute the biotinylated secondary antibody to the desired concentration (e.g., 1 &#181;L of donkey anti-mouse antibody or donkey anti-rabbit antibody into 499 &#181;L of blocking solution). The solution should be stored on ice until use.</li>
	<li>Incubate with the second antibody by shaking off PBST from the slides and quickly covering them with sufficient secondary antibody solution. Incubate the slides in a humidified chamber for 1 h at RT. 
	NOTE: If endogenous biotin is a concern, use a peroxidase-conjugated secondary antibody instead of the biotinylated secondary antibody. Jump to step 1.14 if using a peroxidase-conjugated secondary antibody in step 1.10.</li>
	<li>Wash the slides with PBST for 5 min 3x.</li>
	<li>Prepare the horseradish peroxidase-conjugated streptavidin (SA-HRP) solution (500 &#181;L for two slides) by adding 0.5 &#181;L of SA-HRP into 499 &#181;L of PBS. The final concentration is 1 &#181;g/mL.</li>
	<li>Incubate with the SA-HRP solution. Shake off PBST from the slides and quickly cover the slides with sufficient SA-HRP solution. Incubate the slides in a humidified chamber for 0.5 h at RT.</li>
	<li>Wash the slides with PBST for 5 min 3x.</li>
	<li>Prepare the fluorophore-tyramide solution by diluting fluorophore-tyramide with its dilution buffer according to the manufacturer&#39;s instructions (e.g., 5 &#181;L of fluorophore-tyramide into 496 &#181;L of dilution buffer).</li>
	<li>Perform the signal development with fluorophore-tyramide by shaking off PBST from the slides and quickly covering the slides with sufficient fluorophore-tyramide solution. Incubate in a humidified chamber for 1 min at RT. The incubation time may be adjusted to obtain the desired fluorescence intensity. Stop the reaction by transferring the slides to a Coplin jar containing PBST. Wash slides with PBST for 3 min 2x.</li>
	<li>Signals may be quickly checked under a fluorescence microscope to confirm the result at this stage. If coverslips are not being used, apply a drop of glycerol:PBS (1:1) onto each section to keep the samples moist. Wash slides with PBST for 3 min 2x. Slides may be stored in PBST at 4 &#176;C for a few days before moving to the next step.</li>
</ol>
2. Strip the First Antibody
<ol>
	<li>Place the slides in 275 mL of boiling sodium citrate solution (10 mM, pH = 6.0) for at least 8 min. Keep the solution boiling by placing the slides flat on the bottom of a 14 x 9.5 x 9 cm3 (W x L x H) pipette tip box with a lid and microwaving the solution on 70% power in a 700 W microwave oven for 8 min. If a longer stripping time is preferred, it may be required to top off the buffer using a boiling sodium citrate solution to keep the slides immersed in buffer solution at all times. Remove the pipette tip box from the microwave oven, open the lid, and let the solution cool down at RT for at least 20 min.</li>
	<li>Transfer the slides into a Coplin jar containing PBST. Wash with PBST for 5 min 3x. If the next step if not performed immediately, store the slides in a Coplin jar with PBST at RT for a few hours or at 4 &#176;C for 1-2 days.</li>
</ol>
3. Stain with the Second Antibody
<ol>
	<li>Start from the blocking step and follow same procedures in step 1.5 through step 1.14. At the signal development steps (step 1.15 and step 1.16), use the fluorophore-tyramide in a different fluorescence spectrum. 
	NOTE: Slides can be stripped using this method several times to allow multiplex staining. The last antibody does not require fluorophore-tyramide as the reporter. A fluorophore-conjugated secondary antibody might be used to show signals from the last primary antibody.</li>
	<li>Incubate slides with 2 &#181;g/mL 4&#39;,6-diamidino-2-phenylindole (DAPI) or Hoechst solution for 1 min at RT if nuclear counter staining is needed. Then wash the slides with PBST for 3 min 2x.</li>
</ol>
4. Imaging Using a Fluorescence Microscope to Detect Signals
<ol>
	<li>Mount a coverslip with a drop of mounting medium suitable for immunofluorescence.</li>
	<li>For imaging, use a fluorescence microscope to detect signals of each fluorescence channel. Start with the nuclear staining (DAPI) channel and the 4x lens to locate the tissue on the slide.</li>
	<li>Switch to the 10x lens for imaging. Adjust the exposure time (300 ms) and light source intensity (80% intensity). Adjust these settings if the signal is too bright or too dark. Take pictures of each channel without moving the stage. Refocusing may be needed for each channel. Merge the images from each channel using the microscope&#39;s software or ImageJ (imagej.nih.gov/ij/).</li>
</ol>

<ol>
	<li>Lewis Carl, S. A., Gillete-Ferguson, I., Ferguson, D. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+indirect+immunofluorescence+procedure+for+staining+the+same+cryosection+with+two+mouse+monoclonal+primary+antibodies.">An indirect immunofluorescence procedure for staining the same cryosection with two mouse monoclonal primary antibodies.</a> Journal of Histochemistry and Cytochemistry. 41 (8), 1273-1278 (1993).</li><li>Lan, H. Y., Mu, W., Nikolic-Paterson, D. J., Atkins, R. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel,+simple,+reliable,+and+sensitive+method+for+multiple+immunoenzyme+staining:+use+of+microwave+oven+heating+to+block+antibody+crossreactivity+and+retrieve+antigens.">A novel, simple, reliable, and sensitive method for multiple immunoenzyme staining: use of microwave oven heating to block antibody crossreactivity and retrieve antigens.</a> Journal of Histochemistry and Cytochemistry. 43 (1), 97-102 (1995).</li><li>Tornehave, D., Hougaard, D. M., Larsson, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microwaving+for+double+indirect+immunofluorescence+with+primary+antibodies+from+the+same+species+and+for+staining+of+mouse+tissues+with+mouse+monoclonal+antibodies.">Microwaving for double indirect immunofluorescence with primary antibodies from the same species and for staining of mouse tissues with mouse monoclonal antibodies.</a> Histochemistry and Cell Biology. 113 (1), 19-23 (2000).</li><li>Kim, M., Soontornniyomkij, V., Ji, B., Zhou, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=System-wide+immunohistochemical+analysis+of+protein+co-localization.">System-wide immunohistochemical analysis of protein co-localization.</a> PLoS One. 7 (2), e32043 (2012).</li><li>Bolognesi, M. 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=Multiplex+Staining+by+Sequential+Immunostaining+and+Antibody+Removal+on+Routine+Tissue+Sections.">Multiplex Staining by Sequential Immunostaining and Antibody Removal on Routine Tissue Sections.</a> Journal of Histochemistry and Cytochemistry. 65 (8), 431-444 (2017).</li><li>Toth, Z. E., Mezey, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simultaneous+visualization+of+multiple+antigens+with+tyramide+signal+amplification+using+antibodies+from+the+same+species.">Simultaneous visualization of multiple antigens with tyramide signal amplification using antibodies from the same species.</a> Journal of Histochemistry and Cytochemistry. 55 (6), 545-554 (2007).</li><li>Buchwalow, I., Samoilova, V., Boecker, W., Tiemann, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiple+immunolabeling+with+antibodies+from+the+same+host+species+in+combination+with+tyramide+signal+amplification.">Multiple immunolabeling with antibodies from the same host species in combination with tyramide signal amplification.</a> Acta Histochemica. 120 (5), 405-411 (2018).</li><li>Bauer, M., Schilling, N., Spanel-Borowski, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Limitation+of+microwave+treatment+for+double+immunolabelling+with+antibodies+of+the+same+species+and+isotype.">Limitation of microwave treatment for double immunolabelling with antibodies of the same species and isotype.</a> Histochemistry and Cell Biology. 116 (3), 227-232 (2001).</li><li>Pirici, D., 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=Antibody+elution+method+for+multiple+immunohistochemistry+on+primary+antibodies+raised+in+the+same+species+and+of+the+same+subtype.">Antibody elution method for multiple immunohistochemistry on primary antibodies raised in the same species and of the same subtype.</a> Journal of Histochemistry and Cytochemistry. 57 (6), 567-575 (2009).</li><li>Glass, G., Papin, J. A., Mandell, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=SIMPLE:+a+sequential+immunoperoxidase+labeling+and+erasing+method.">SIMPLE: a sequential immunoperoxidase labeling and erasing method.</a> Journal of Histochemistry and Cytochemistry. 57 (10), 899-905 (2009).</li><li>Zhang, W., 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=Fully+automated+5-plex+fluorescent+immunohistochemistry+with+tyramide+signal+amplification+and+same+species+antibodies.">Fully automated 5-plex fluorescent immunohistochemistry with tyramide signal amplification and same species antibodies.</a> Laboratory Investigation. 97 (7), 873-885 (2017).</li><li>Paul, A., Laufer, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endogenous+biotin+as+a+marker+of+adrenocortical+cells+with+steroidogenic+potential.">Endogenous biotin as a marker of adrenocortical cells with steroidogenic potential.</a> Molecular and Cellular Endocrinology. 336 (1-2), 133-140 (2011).</li><li>Bussolati, G., Gugliotta, P., Volante, M., Pace, M., Papotti, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Retrieved+endogenous+biotin:+a+novel+marker+and+a+potential+pitfall+in+diagnostic+immunohistochemistry.">Retrieved endogenous biotin: a novel marker and a potential pitfall in diagnostic immunohistochemistry.</a> Histopathology. 31 (5), 400-407 (1997).</li><li>Wang, H., Pevsner, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+endogenous+biotin+in+various+tissues:+novel+functions+in+the+hippocampus+and+implications+for+its+use+in+avidin-biotin+technology.">Detection of endogenous biotin in various tissues: novel functions in the hippocampus and implications for its use in avidin-biotin technology.</a> Cell and Tissue Research. 296 (3), 511-516 (1999).</li></ol>

The authors have nothing to disclose.

Multiplex immunostaining is useful to examine the cellular colocalization of two or more antigens. This widely used technique gives convincing colocalization results when primary antibodies are conjugated with different reporters (direct staining). However, direct staining usually provides weaker signals compared to indirect staining, which involves conjugated secondary antibodies to detect the primary antibodies. In indirect staining, a high-quality multiplex immunostaining result relies on whether the secondary antibod...

In multiplex immunostaining, direct staining using conjugated primary antibodies can provide informative results. Without using secondary antibodies, the direct staining method has a low risk of false colocalization signals from antibody cross-reactivity. However, the conjugated reporters (fluorophore, enzymes) or biotin on the primary antibody limit its future use. Alternatively, indirect immunostaining usually provides stronger signals by using an unconjugated primary antibody with a labeled secondary antibody. Ideally, unconjugated primary antibodies used in multiplex immunostaining should come from different host species to avoid antibody cross-reactivity. However, the appropriate combination of primary antibodies from different host species is not always available.
Several methods have been established to eliminate the risk of the secondary antibody reacting with an undesired primary antibody. One common method is the use of a F(ab) monomeric antibody to block any remaining binding epitopes on the first primary antibody complex before staining with the second primary antibody1. Antibody stripping, which is similar to the strip and reprobe of a Western blot sheet, removes the previously stained antibody complex without stripping the deposition of detectable reporter molecules such as 3,3&#39;-diaminobenzidine tetrahydrochloride (DAB)2 and the fluorescent tyramide deposition3. With this method, reporter molecules in different colors can show a multiplex result on the same slide. The multiplex staining is also achievable by the complete removal of the previously deposited layers of antibodies and the alignment of subsequently acquired images from other antibodies4,5. These methods all give reliable results, though each method has its limitations and requires either complicated procedures or a special imaging system.
The present protocol shows the application of an antibody stripping method with the use of commonly available buffers. This protocol can be used to perform multiplex immunofluorescent staining on formalin-fixed paraffin-embedded (FFPE) mouse adrenal sections with two unlabeled primary antibodies from the same host species.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Antifade Mounting Medium</td>
			<td>Vector Laboratories</td>
			<td>H-1000</td>
			<td></td>
		</tr>
		<tr>
			<td>Biotinylated donkey anti-mouse</td>
			<td>JacksonImmuno</td>
			<td>715-066-151</td>
			<td>1:500 dilution</td>
		</tr>
		<tr>
			<td>Biotinylated donkey anti-rabbit</td>
			<td>JacksonImmuno</td>
			<td>711-066-152</td>
			<td>1:500 dilution</td>
		</tr>
		<tr>
			<td>DAPI</td>
			<td>BioLegend</td>
			<td>422801</td>
			<td>2 &#956;g/mL in distilled water</td>
		</tr>
		<tr>
			<td>Fluorescence microscope</td>
			<td>ECHO</td>
			<td>Revolve 4</td>
			<td></td>
		</tr>
		<tr>
			<td>Horseradish peroxidase-conjugated streptavidin</td>
			<td>JacksonImmuno</td>
			<td>016-030-084</td>
			<td>1:1000 dilution</td>
		</tr>
		<tr>
			<td>Microwave oven, 700W</td>
			<td>General Electric</td>
			<td>JEM3072DH1BB</td>
			<td></td>
		</tr>
		<tr>
			<td>Mouse anti-CYP2F2</td>
			<td>Santa Cruz,</td>
			<td>SC-374540</td>
			<td>1:250 dilution</td>
		</tr>
		<tr>
			<td>Mouse anti-TH</td>
			<td>Santa Cruz,</td>
			<td>SC-25269</td>
			<td>1:1000 dilution</td>
		</tr>
		<tr>
			<td>Normal donkey serum</td>
			<td>JacksonImmuno</td>
			<td>017-000-121</td>
			<td>2% serum in PBST</td>
		</tr>
		<tr>
			<td>Rabbit anti-20&#945;HSD</td>
			<td>Kerafast,</td>
			<td>EB4002</td>
			<td>1:500 dilution</td>
		</tr>
		<tr>
			<td>Rabbit anti-3&#946;HSD</td>
			<td>TransGenic,</td>
			<td>KO607</td>
			<td>1:250 dilution</td>
		</tr>
		<tr>
			<td>Rabbit anti-TH</td>
			<td>NOVUS,</td>
			<td>NB300-109</td>
			<td>1:1000 dilution</td>
		</tr>
		<tr>
			<td>Rabbit anti-&#946;-catenin</td>
			<td>Abcam,</td>
			<td>ab32572</td>
			<td>1:500 dilution</td>
		</tr>
		<tr>
			<td>Streptavidin Horseradish Peroxidase (SA-HRP)</td>
			<td>JacksonImmuno</td>
			<td>016-303-084</td>
			<td>1:1000 dilution</td>
		</tr>
		<tr>
			<td>TSA Cy3 Tyramide</td>
			<td>PerkinElmer</td>
			<td>SAT704B001EA</td>
			<td>1:100 dilution</td>
		</tr>
		<tr>
			<td>TSA Fluorescein Tyramide</td>
			<td>PerkinElmer</td>
			<td>SAT701001EA</td>
			<td>1:100 dilution</td>
		</tr>
	</tbody>
</table>

microwaving and fluorophore-tyramide for multiplex immunostaining on mouse adrenals &#8722; using unconjugated primary antibodies from the same host species

Immunostaining is widely used in biomedical research to show the cellular expression pattern of a given protein. Multiplex immunostaining allows labeling using multiple primary antibodies. To minimize antibody cross-reactivity, multiplex immunostaining using indirect staining requires unlabeled primary antibodies from different host species. However, the appropriate combination of different species antibodies is not always available. Here, we describe a method of using unlabeled primary antibodies from the same host species (e.g., in this case both antibodies are from rabbit) for multiplex immunofluorescence on formalin-fixed paraffin-embedded (FFPE) mouse adrenal sections. This method uses the same procedure and reagents used in the antigen retrieval step to strip the activity of the previously stained primary antibody complex. Slides were stained with the first primary antibody using a general immunostaining protocol followed by a binding step with a biotinylated secondary antibody. Then, an avidin-biotin-peroxidase signal development method was used with fluorophore-tyramide as the substrate. The immunoactivity of the first primary antibody complex was stripped through immersion in a microwaved boiling sodium citrate solution for 8 min. The insoluble fluorophore-tyramide deposition remained on the sample, which allowed the slide to be stained with other primary antibodies. Although this method eliminates most false positive signals, some background from antibody cross-reactivity may remain. If the samples are enriched with endogenous biotin, a peroxidase-conjugated secondary antibody may be used to replace the biotinylated secondary antibody to avoid the false positive from recovered endogenous biotin.

The results were obtained from samples treated with all steps described including the antigen retrieval step 1.2. All secondary antibodies used here were biotinylated. Fluorophore-tyramide was used to develop signals from the first and second primary antibodies. Images were captured using a fluorescence microscope equipped with a FITC cube (for green fluorescence), a TxRED cube (for Cy3), and a DAPI cube (for DAPI).
Micr...

Watch this Scientific Journal Video about Microwaving and Fluorophore-Tyramide for Multiplex Immunostaining on Mouse Adrenals Ã¢Ë†' Using Unconjugated Primary Antibodies from the Same Host Species at 

Microwaving and Fluorophore-Tyramide for Multiplex Immunostaining on Mouse Adrenals &#8722; Using Unconjugated Primary Antibodies from the Same Host Species

Several different methods have been established for multiplex immunostaining using primary antibodies from the same host species. Here, we describe the use of microwave-mediated antibody stripping and of fluorophore-tyramide to block antibody cross-reactivity during multiplex immunostaining on formalin-fixed paraffin-embedded mouse adrenal sections.

Immunostaining is widely used in biomedical research to show the cellular expression pattern of a given protein. Multiplex immunostaining allows labeling ...

microwaving-fluorophore-tyramide-for-multiplex-immunostaining-on

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6.8K Views.  Henan University of Science and Technology. Several different methods have been established for multiplex immunostaining using primary antibodies from the same host species. Here, we describe the use of microwave-mediated antibody stripping and of fluorophore-tyramide to block antibody cross-reactivity during multiplex immunostaining on formalin-fixed paraffin-embedded mouse adrenal sections.

Video: Microwaving and Fluorophore-Tyramide for Multiplex Immunostaining on Mouse Adrenals − Using Unconjugated Primary Antibodies from the Same Host Species

Alginate Encapsulation of Pluripotent Stem Cells Using a Co-axial Nozzle

Pluripotent stem cells (PS cells) are the focus of intense research due to their role in regenerative medicine and drug screening. However, the development of a mass culture system would be required for using PS cells in these applications. Suspension culture is one promising culture method for the mass production of PS cells, although some issues such as controlling aggregation and limiting shear stress from the culture medium are still unsolved. In order to solve these problems, we developed a method of calcium alginate (Alg-Ca) encapsulation using a co-axial nozzle. This method can control the size of the capsules easily by co-flowing N2 gas. The controllable capsule diameter must be larger than 500 &#181;m because too high a flow rate of N2 gas causes the breakdown of droplets and thus heterogeneous-sized capsules. Moreover, a low concentration of Alg-Na and CaCl2 causes non-spherical capsules. Although an Alg-Ca capsule without a coating of Alg-PLL easily dissolves enabling the collection of cells, they can also potentially leak out from capsules lacking an Alg-PLL coating. Indeed, an alginate-PLL coating can prevent cellular leakage but is also hard to break. This technology can be used to research the stem cell niche as well as the mass production of PS cells because encapsulation can modify the micro-environment surrounding cells including the extracellular matrix and the concentration of secreted factors.

We established a method of encapsulating pluripotent stem cells (PS cells) into alginate hydrogel capsules using a co-axial nozzle. This prevents cells from aggregating excessively and limits the shear stress experienced by cells in suspension culture. The technique is applicable to the mass production of PS cells as well as research on stem cell niche.

Pluripotent stem cells (PS cells) are the focus of intense research due to their role in regenerative medicine and drug screening.  However, the ...

Using Isolated Mitochondria from Minimal Quantities of Mouse Skeletal Muscle for High throughput Microplate Respiratory Measurements

Skeletal muscle mitochondria play a specific role in many disease pathologies. As such, the measurement of oxygen consumption as an indicator of mitochondrial function in this tissue has become more prevalent. Although many technologies and assays exist that measure mitochondrial respiratory pathways in a variety of cells, tissue and species, there is currently a void in the literature in regards to the compilation of these assays using isolated mitochondria from mouse skeletal muscle for use in microplate based technologies. Importantly, the use of microplate based respirometric assays is growing among mitochondrial biologists as it allows for high throughput measurements using minimal quantities of isolated mitochondria. Therefore, a collection of microplate based respirometric assays were developed that are able to assess mechanistic changes/adaptations in oxygen consumption in a commonly used animal model. The methods presented herein provide step-by-step instructions to perform these assays with an optimal amount of mitochondrial protein and reagents, and high precision as evidenced by the minimal variance across the dynamic range of each assay.

The methods presented provide step-by-step instructions for the performance of a collection of microplate based respirometric assays using isolated mitochondria from minimal quantities of mouse skeletal muscle. These assays are able to measure mechanistic changes/adaptations in mitochondrial oxygen consumption in a commonly used animal model.

Skeletal muscle mitochondria play a specific role in many disease pathologies. As such, the measurement of oxygen consumption as an indicator of ...

Generating Primary Fibroblast Cultures from Mouse Ear and Tail Tissues

Primary cells are derived directly from tissue and are thought to be more representative of the physiological state of cells in vivo than established cell lines. However, primary cell cultures usually have a finite life span and need to be frequently re-established. Fibroblasts are an easily accessible source of primary cells. Here, we discuss a simple and quick experimental procedure to establish primary fibroblast cultures from ears and tails of mice. The protocol can be used to establish primary fibroblast cultures from ears stored at RT for up to 10 days. When the protocol is carefully followed, contaminations are unlikely to occur despite the use of non-sterile tissue stored for extended time in some cases. Fibroblasts proliferate rapidly in culture and can be expanded to substantial numbers before undergoing replicative senescence.

We describe a simple and quick experimental procedure for generating primary fibroblasts from the ears and tails of mice. The procedure does not require special animal training and can be used for the generation of fibroblast cultures from ears stored at RT for up to 10 days.

Primary cells are derived directly from tissue and are thought to be more representative of the physiological state of cells in vivo than established cell ...

The Production of Pluripotent Stem Cells from Mouse Amniotic Fluid Cells Using a Transposon System

Induced pluripotent stem (iPS) cells are generated from mouse and human somatic cells by forced expression of defined transcription factors using different methods. Here, we produced iPS cells from mouse amniotic fluid cells, using a non-viral-based transposon system. All obtained iPS cell lines exhibited characteristics of pluripotent cells, including the ability to differentiate toward derivatives of all three germ layers in vitro and in vivo. This strategy opens up the possibility of using cells from diseased fetuses to develop new therapies for birth defects.

In this study, we generate induced pluripotent stem cells from mouse amniotic fluid cells, using a non-viral-based transposon system.

Induced pluripotent stem (iPS) cells are generated from mouse and human somatic cells by forced expression of defined transcription factors using ...

Induced Pluripotent Stem Cell Generation from Blood Cells Using Sendai Virus and Centrifugation

The recent development of human induced pluripotent stem cells (hiPSCs) proved that mature somatic cells can return to an undifferentiated, pluripotent state. Now, reprogramming is done with various types of adult somatic cells: keratinocytes, urine cells, fibroblasts, etc. Early experiments were usually done with dermal fibroblasts. However, this required an invasive surgical procedure to obtain fibroblasts from the patients. Therefore, suspension cells, such as blood and urine cells, were considered ideal for reprogramming because of the convenience of obtaining the primary cells. Here, we report an efficient protocol for iPSC generation from peripheral blood mononuclear cells (PBMCs). By plating the transduced PBMCs serially to a new, matrix-coated plate using centrifugation, this protocol can easily provide iPSC colonies. This method is also applicable to umbilical cord blood mononuclear cells (CBMCs). This study presents a simple and efficient protocol for the reprogramming of PBMCs and CBMCs.

We propose a protocol for reprogramming peripheral blood mononuclear cells (PBMCs) into induced pluripotent stem cells (iPSCs). By plating the transduced blood cells onto matrix-coated plates with centrifugation, iPSCs are successfully induced from floating cells. This technique suggests a simple and effective reprogramming protocol for cells such as PBMCs and CBMCs.

The recent development of human induced pluripotent stem cells (hiPSCs) proved that mature somatic cells can return to an undifferentiated, pluripotent ...

Whole-cell Patch-clamp Recordings of Isolated Primary Epithelial Cells from the Epididymis

The epididymis is an essential organ for sperm maturation and reproductive health. The epididymal epithelium consists of intricately connected cell types that are distinct not only in molecular and morphological features but also in physiological properties. These differences reflect their diverse functions, which together establish the necessary microenvironment for the post-testicular sperm development in the epididymal lumen. The understanding of the biophysical properties of the epididymal epithelial cells is critical for revealing their functions in sperm and reproductive health, under both physiological and pathophysiological conditions. While their functional properties have yet to be fully elucidated, the epididymal epithelial cells can be studied using the patch-clamp technique, a tool for measuring the cellular events and the membrane properties of single cells. Here, we describe the methods of cell isolation and whole-cell patch-clamp recording to measure the electrical properties of primary dissociated epithelial cells from the rat cauda epididymides.

We present a protocol that combines cell isolation and whole-cell patch-clamp recording to measure the electrical properties of the primary dissociated epithelial cells from the rat cauda epididymides. This protocol allows for investigation of the functional properties of primary epididymal epithelial cells to further elucidate the physiological role of the epididymis.

The epididymis is an essential organ for sperm maturation and reproductive health. The epididymal epithelium consists of intricately connected cell types ...

Genetic Engineering of Primary Mouse Intestinal Organoids Using Magnetic Nanoparticle Transduction Viral Vectors for Frozen Sectioning

Intestinal organoid cultures provide a unique opportunity to investigate intestinal stem cell and crypt biology in vitro, although efficient approaches to manipulate gene expression in organoids have made limited progress in this arena. While CRISPR/Cas9 technology allows for precise genome editing of cells for organoid generation, this strategy requires extensive selection and screening by sequence analysis, which is both time-consuming and costly. Here, we provide a detailed protocol for efficient viral transduction of intestinal organoids. This approach is rapid and highly efficient, thus decreasing the time and expense inherent in CRISPR/Cas9 technology. We also present a protocol to generate frozen sections from intact organoid cultures for further analysis with immunohistochemical or immunofluorescent staining, which can be used to confirm gene expression or silencing. After successful transduction of viral vectors for gene expression or silencing is achieved, intestinal stem cell and crypt function can be rapidly assessed. Although most organoid studies employ in vitro assays, organoids can also be delivered to mice for in vivo functional analyses. Moreover, our approaches are advantageous for predicting therapeutic responses to drugs because currently available therapies generally function by modulating gene expression or protein function rather than altering the genome.

We describe step-by-step instructions to: 1) efficiently engineer intestinal organoids using magnetic nanoparticles for lenti- or retroviral transduction, and, 2) generate frozen sections from engineered organoids. This approach provides a powerful tool to efficiently alter gene expression in organoids for investigation of downstream effects.

Intestinal organoid cultures provide a unique opportunity to investigate intestinal stem cell and crypt biology in vitro, although efficient approaches to ...

Induction and Validation of Cellular Senescence in Primary Human Cells

Cellular senescence is a state of permanent cell cycle arrest activated in response to different damaging stimuli. Activation of cellular senescence is a hallmark of various pathophysiological conditions including tumor suppression, tissue remodeling and aging. The inducers of cellular senescence in vivo are still poorly characterized. However, a number of stimuli can be used to promote cellular senescence ex vivo. Among them, most common senescence-inducers are replicative exhaustion, ionizing and non-ionizing radiation, genotoxic drugs, oxidative stress, and demethylating and acetylating agents. Here, we will provide detailed instructions on how to use these stimuli to induce fibroblasts into senescence. This protocol can easily be adapted for different types of primary cells and cell lines, including cancer cells. We also describe different methods for the validation of senescence induction. In particular, we focus on measuring the activity of the lysosomal enzyme Senescence-Associated &#946;-galactosidase (SA-&#946;-gal), the rate of DNA synthesis using 5-ethynyl-2&#39;-deoxyuridine (EdU) incorporation assay, the levels of expression of the cell cycle inhibitors p16 and p21, and the expression and secretion of members of the Senescence-Associated Secretory Phenotype (SASP). Finally, we provide example results and discuss further applications of these protocols.

Here, we discuss a series of protocols for induction and validation of cellular senescence in cultured cells. We focus on different senescence-inducing stimuli and describe the quantification of common senescence-associated markers. We provide technical details using fibroblasts as a model, but the protocols can be adapted to various cellular models.

Cellular senescence is a state of permanent cell cycle arrest activated in response to different damaging stimuli. Activation of cellular senescence is a ...

Tissue Preparation and Immunostaining of Mouse Craniofacial Tissues and Undecalcified Bone

Tissue immunostaining provides highly specific and reliable detection of proteins of interest within a given tissue. Here we describe a complete and simple protocol to detect protein expression during craniofacial morphogenesis/pathogenesis using mouse craniofacial tissues as examples. The protocol consists of preparation and cryosectioning of tissues, indirect immunofluorescence, image acquisition, and quantification. In addition, a method for preparation and cryosectioning of undecalcified hard tissues for immunostaining is described, using craniofacial tissues and long bones as examples. Those methods are key to determine the protein expression and morphological/anatomical changes in various tissues during craniofacial morphogenesis/pathogenesis. They are also applicable to other tissues with appropriate modifications. Knowledge of the histology and high quality of sections are critical to draw scientific conclusions from experimental outcomes. Potential limitations of this methodology include but are not limited to specificity of antibodies and difficulties of quantification, which are also discussed here.

Here, we present a detailed protocol to detect and quantify protein levels during craniofacial morphogenesis/pathogenesis by immunostaining using mouse craniofacial tissues as examples. In addition, we describe a method for preparation and cryosectioning of undecalcified hard tissues from young mice for immunostaining.

Tissue immunostaining provides highly specific and reliable detection of proteins of interest within a given tissue. Here we describe a complete and ...

Confocal Live Imaging of Shoot Apical Meristems from Different Plant Species

The shoot apical meristem (SAM) functions as a conserved stem cell reservoir and it generates almost all aboveground tissues during the postembryonic development. The activity and morphology of SAMs determine important agronomic traits, such as shoot architecture, size and number of reproductive organs, and most importantly, grain yield. Here, we provide a detailed protocol for analyzing both the surface morphology and the internal cellular structure of the living SAMs from different species through laser scanning confocal microscope. The whole procedure from the sample preparation to the acquisition of high resolution three-dimensional (3D) images can be accomplished within as short as 20 minutes. We demonstrate that this protocol is highly efficient for studying not only the inflorescence SAMs of the model species but also the vegetative meristems from different crops, providing a simple but powerful tool to study the organization and development of meristems across different plant species.

This protocol presents how to live image and analyze the shoot apical meristems from different plant species using laser scanning confocal microscopy.

The shoot apical meristem (SAM) functions as a conserved stem cell reservoir and it generates almost all aboveground tissues during the postembryonic ...