Staining of paraffin sections
<ol>
<li>Dewax slides with Xylene (Fisher X3S-4) 3x for 5 minutes each (change xylene every month depending on use, xylene is TOXIC). Use dishes and covers for 20 slides from Fisher ref 08-812-1A and racks made to fit these dishes. 200 ml liquid per dish.</li>
<li>Hydrate through alcohol gradient as follows (change gradient every 2 weeks): 
<ul>
<li>2x in 100% ethanol (Fisher # A406-20) for 2 min each </li>
<li>2x in 95% ethanol for 2 min each </li>
<li>1x in 70% ethanol for 2 min </li>
<li>1x in 50% ethanol for 2 min </li>
<li>1x in 30% ethanol for 2 min </li>
<li>1x ddH2O for 2 min</li>
</ul>
</li>
<li>Soak in DPBS for 5 min (DPBS = Dulbecco's modified Phosphate Buffered Saline with Ca2+ and Mg2+).</li>
</ol>
Antigen recovery:
<ol>
<li>Pre-heat the Na-Citrate buffer (10 mM, pH 6.5) in the microwave. </li>
<li>Cook the slides for 15 min in the microwave. The slides should never dry so check every min and add Na-Citrate when necessary.</li>
<li>Let cool at room temperature.</li>
<li>Block endogenous peroxidase activity with 1% H2O2 in DPBS for 20 min (1.5 ml of 30% stock Sigma H-1009 in 50 ml DPBS).</li>
<li>Soak in DPBS 3 x 5 min.</li>
<li>Block non-specific sites by incubating overnight at +4&deg;C in DPBS + 5% bovine serum albumin (BSA) + 0.1% Na Azide + 5% serum. Note: Choice of serum will depend on species in which antibodies used for staining were made. Block with serum from the species in which the secondary Ab (conjugated to biotin) was made. If this is not available, use serum from a species different from the one in which the primary Ab was made. </li>
<li>Block the biotin sites with the avidin/biotin blocking kit (Vector laboratories catalog # SP-2001): 
<ul>
<li>Incubate with Avidin D for 15 min. Rinse briefly with DPBS.</li>
<li>Incubate with the biotin solution for 15 min.</li>
</ul>
</li>
<li>Incubate in primary Ab for 2 hrs at room temperature, in DPBS + 2% BSA + 0.1 % NaAzide + 2% serum (same as for Blocking step).</li>
<li>Soak in PBS 3 x 5 min.</li>
<li>Incubate with the secondary Ab conjugated with biotin for 1 hour at room temperature in DPBS + 2% BSA + 0.1% Na Azide + 2% serum (same as used for the blocking step).</li>
<li>Prepare ABC reagent at the same time because it has to develop for at least 30 min before use!!! (see Materials)</li>
<li>Prepare in a 50 ml conical tube. In 15 ml DPBS (no serum, no azide) add 3 drops of reagent A, mix and add 3 drops of reagent B and mix. Avoid squeezing the bottles, rather wait for the drops to form on their own. ABC kit Vectastain PK-6100 from Vector Labs.</li>
<li>Soak in DPBS 3 x 5 min.</li>
<li>Incubate with ABC reagent for 30-45 min at room temperature.</li>
<li>Soak in DPBS 3 x 5 min.</li>
<li>Prepare DAB peroxidase substrate (Vector Labs # SK-4100) in 5 ml ddH2O in a glass vial immediately before use (see Materials) 
<ul>
<li>2 drops of buffer stock solution, mix</li>
<li>4 drops of DAB, mix (should become slightly brown)</li>
<li>2 drops H2O2, mix</li>
</ul>
</li>
<li>Drop the DAB substrate on top of the slides and watch for brown staining.</li>
<li>Dip slides into ice + tap water to stop the reaction.</li>
<li>Rinse under cold tap water for 5 min.</li>
<li>Counterstain with Hematoxylin (20 sec; Fisher CS401-D) and rinse in tap water until water comes out clear.</li>
<li>Dehydrate through alcohol gradient starting at 30% ethanol up to 100% ethanol (2 min each).</li>
<li>Soak in xylene 3 x 5 min. </li>
<li>Mount with Permount (Fisher # SP15-100): put some above the section on the slide and press slowly onto the section with a coverslip without air bubbles. Do not move the coverslip until completely dry, which&nbsp;takes ~ 24 hours. </li>
</ol>

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<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">	
		
		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Xylene</td>
<td>&nbsp;</td>
<td>Fisher</td>
<td>X3S-4</td>
<td>Change xylene every month depending on use. Xylene is TOXIC.</td>
</tr>
<tr>
<td>100% ethanol</td>
<td>&nbsp;</td>
<td>Fisher</td>
<td>A406-20</td>
<td>Use to make EtOH gradient.</td>
</tr>
<tr>
<td>DPBS</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>Dulbecco&#x2019;s modified Phosphate Buffered Saline WITH Ca2+ and Mg2+</td>
</tr>
<tr>
<td>Na-Citrate buffer</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>10 mM, pH 6.5</td>
</tr>
<tr>
<td>H2O2</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>H-1009</td>
<td>30% stock => Dilute to 1% in DPBS</td>
</tr>
<tr>
<td>Blocking solution</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>DPBS + 5% bovine serum albumin (BSA) + 0.1% Na Azide + 5% serum. </td>
</tr>
<tr>
<td>BSA</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Sodium Azide</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>NaAzide</td>
</tr>
<tr>
<td>avidin/biotin blocking kit</td>
<td>&nbsp;</td>
<td>Vector laboratories</td>
<td>SP-2001</td>
<td>&nbsp;</td>
<tr>
<td>Ab buffer</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>DPBS + 2% BSA + 0.1% Na Azide + 2% serum (same as used for the blocking step)</td>
</tr>
<tr>
<td>ABC kit Vectastain PK-6100</td>
<td>&nbsp;</td>
<td>Vector Laboratories</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>DAB peroxidase substrate</td>
<td>&nbsp;</td>
<td>Vector Laboratories</td>
<td>SK-4100</td>
<td>&nbsp;</td>
<tr>
<td>ddH2O</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Hematoxylin</td>
<td>&nbsp;</td>
<td>Fisher</td>
<td>CS401-D</td>
<td>counterstain</td>
</tr>
<tr>
<td>Permount</td>
<td>&nbsp;</td>
<td>Fisher</td>
<td>SP15-100</td>
<td>&nbsp;</td>
<tr>
<td>Slides and cover-slips</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>glass</td>
</tr>		</tbody>
		</table>
		</div>

immunohistochemistry: paraffin sections using the vectastain abc kit from vector labs

Immunohistochemistry (IHC) is a valuable technique utilized to localize/visualize protein expression in a mounted tissue section using specific antibodies. There are two methods: the direct and indirect method. In this experiment, we will only describe the use of indirect IHC staining. Indirect IHC staining utilizes highly specific primary and biotin-conjugated secondary antibodies. Primary antibodies are utilized to discretely identify proteins of interest by binding to a specific epitope, while secondary antibodies subtract for non-specific background staining and amplify signal by forming complexes to the primary antibody. Slides can either be generated from frozen sections, or paraffin embedded sections mounted on glass slides. In this protocol, we discuss the preparation of paraffin-embedded sections by dewaxing, hydration using an alcohol gradient, heat induced antigen retrieval, and blocking of endogenous peroxidase activity and non-specific binding sites. Some sections are then stained with antibodies specific for T cell marker CD8 and while others are stained for tyrosine hydroxylase. The slides are subsequently treated with appropriate secondary antibodies conjugated to biotin, then developed utilizing avidin-conjugated horseradish peroxidase (HRP) with Diaminiobenzidine (DAB) as substrate. Following development, the slides are counterstained for contrast, and mounted under coverslips with permount. After adequate drying, these slides are then ready for imaging.

Watch this Scientific Journal Video about Immunohistochemistry: Paraffin Sections Using the Vectastain ABC Kit from Vector Labs at JoVE.com

Immunohistochemistry: Paraffin Sections Using the Vectastain ABC Kit from Vector Labs

Immunohistochemistry (IHC) is a valuable technique utilized to localize/visualize protein expression in a mounted tissue section using specific ...

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69.2K Views.  University of California, Irvine (UCI). Immunohistochemistry: Paraffin Sections Using the Vectastain ABC Kit from Vector Labs

Video: Immunohistochemistry: Paraffin Sections Using the Vectastain ABC Kit from Vector Labs

Purifying Plasmid DNA from Bacterial Colonies Using the Qiagen Miniprep Kit

Plasmid DNA purification from E. coli is a core technique for molecular cloning. Small scale purification (miniprep) from less than 5 ml of bacterial culture is a quick way for clone verification or DNA isolation, followed by further enzymatic reactions (polymerase chain reaction and restriction enzyme digestion). Here, we video-recorded the general procedures of miniprep through the QIAGEN's QIAprep 8 Miniprep Kit, aiming to introducing this highly efficient technique to the general beginners for molecular biology techniques. The whole procedure is based on alkaline lysis of E. coli cells followed by adsorption of DNA onto silica in the presence of high salt. It consists of three steps: 1) preparation and clearing of a bacterial lysate, 2) adsorption of DNA onto the QIAprep membrane, 3) washing and elution of plasmid DNA. All steps are performed without the use of phenol, chloroform, CsCl, ethidium bromide, and without alcohol precipitation. It usually takes less than 2 hours to finish the entire procedure.

Plasmid DNA purification from E. coli is a core technique for molecular cloning. Small scale purification (miniprep) from less than 5 ml of bacterial ...

Enrichment of NK Cells from Human Blood with the RosetteSep Kit from StemCell Technologies

Natural killer (NK) cells are large granular cytotoxic lymphocytes that belong to the innate immune system and play major roles in fighting against cancer and infections, but are also implicated in the early stages of pregnancy and transplant rejection. These cells are present in peripheral blood, from which they can be isolated. Cells can be isolated using either positive or negative selection. For positive selection we use antibodies directed to a surface marker present only on the cells of interest whereas for negative selection we use cocktails of antibodies targeted to surface markers present on all cells but the cells of interest. This latter technique presents the advantage of leaving the cells of interest free of antibodies, thereby reducing the risk of unwanted cell activation or differenciation. In this video-protocol we demonstrate how to separate NK cells from human blood by negative selection, using the RosetteSep kit from StemCell technologies. The procedure involves obtaining human peripheral blood (under an institutional review board-approved protocol to protect the human subjects) and mixing it with a cocktail of antibodies that will bind to markers absent on NK cells, but present on all other mononuclear cells present in peripheral blood (e.g., T lymphocytes, monocytes...). The antibodies present in the cocktail are conjugated to antibodies directed to glycophorin A on erythrocytes. All unwanted cells and red blood cells will therefore be trapped in complexes. The mix of blood and antibody cocktail is then diluted, overlayed on a Histopaque gradient, and centrifuged. NK cells (&gt;80% pure) can be collected at the interface between the Histopaque and the diluted plasma. Similar cocktails are available for enrichment of other cell populations, such as human T lymphocytes.

Natural killer cells are a small population of lymphocytes. Here we show how to isolate these cells from human blood by negative selection, using a kit from StemCell Technologies. The cells obtained are viable and untouched by antibodies, and therefore ready to be used for a number of procedures.

Natural killer (NK) cells are large granular cytotoxic lymphocytes that belong to the innate immune system and play major roles in fighting against cancer ...

RNA Extraction from Neuroprecursor Cells Using the Bio-Rad Total RNA Kit

Immunohistochemistry on Paraffin Sections of Mouse Epidermis Using Fluorescent Antibodies

In the epidermis, immunohistochemistry is an efficient means of localizing specific proteins to their relative expression compartment; namely the basal, suprabasal, and stratum corneum layers. The precise localization within the epidermis of a particular protein lends clues toward its functional role within the epidermis. In this chapter, we describe a reliable method for immunolocalization within the epidermis modified for both frozen and paraffin sections that we use very routinely in our laboratory. Paraffin sections generally provide much better morphology, hence, superior results and photographs; however, not all antibodies will work with the harsh fixation and treatment involved in their processing. Therefore, the protocol for frozen sectioning is also included. Within paraffin sectioning, two fixation protocols are described (Bouin's and paraformaldehyde); the choice of fixative will be directly related to the antibody specifications and may require another fixing method.

We describe a reliable method for immunolocalization within the epidermis modified for both frozen and paraffin sections that we use very routinely in our laboratory.

In the epidermis, immunohistochemistry is an efficient means of localizing specific proteins to their relative expression compartment; namely the basal, ...

Paraffin-Embedded and Frozen Sections of Drosophila Adult Muscles

The molecular characterization of muscular dystrophies and myopathies in humans has revealed the complexity of muscle disease and genetic analysis of muscle specification, formation and function in model systems has provided valuable insight into muscle physiology. Therefore, identifying and characterizing molecular mechanisms that underlie muscle damage is critical. The structure of adult Drosophila multi-fiber muscles resemble vertebrate striated muscles 1 and the genetic tractability of Drosophila has made it a great system to analyze dystrophic muscle morphology and characterize the processes affecting muscular function in ageing adult flies 2. Here we present the histological technique for preparing paraffin-embedded and frozen sections of Drosophila thoracic muscles. These preparations allow for the tissue to be stained with classical histological stains and labeled with protein detecting dyes, and specifically cryosections are ideal for immunohistochemical detection of proteins in intact muscles. This allows for analysis of muscle tissue structure, identification of morphological defects, and detection of the expression pattern for muscle/neuron-specific proteins in Drosophila adult muscles. These techniques can also be slightly modified for sectioning of other body parts.

Paraffin-Embedded and Frozen Sections of Drosophila Adult Muscles

Identification of mechanisms underlying muscle damage is crucial. Here we present the histological technique for preparing paraffin-embedded and frozen sections of Drosophila thoracic muscles. This allows analysis of muscle morphology and localization of protein and other muscle cell components.

The molecular characterization of muscular dystrophies and myopathies in humans has revealed the complexity of muscle disease and genetic analysis of ...

Mouse Sperm Cryopreservation and Recovery using the I&middot;Cryo Kit

Thousands of new genetically modified (GM) strains of mice have been created since the advent of transgenesis and knockout technologies. Many of these valuable animals exist only as live animals, with no backup plan in case of emergency. Cryopreservation of embryos can provide this backup, but is costly, can be a lengthy procedure, and generally requires a large number of animals for success. Since the discovery that mouse sperm can be successfully cryopreserved with a basic cryoprotective agent (CPA) consisting of 18&#37; raffinose and 3&#37; skim milk, sperm cryopreservation has become an acceptable and cost-effective procedure for archiving, distributing and recovery of these valuable strains.
 Here we demonstrate a newly developed I&bull;Cryo kit for mouse sperm cryopreservation. Sperm from five commonly-used strains of inbred mice were frozen using this kit and then recovered. Higher protection ratios of sperm motility (&gt; 60&#37;) and rapid progressive motility (&gt; 45&#37;) compared to the control (basic CPA) were seen for sperm frozen with this kit in 5 inbred mouse strains. Two cell stage embryo development after IVF with the recovered sperm was improved consistently in all 5 mouse strains examined. Over a 1.5 year period, 49 GM mouse lines were archived by sperm cryopreservation with the I&bull;Cryo kit and later recovered by IVF.

Mouse Sperm Cryopreservation and Recovery using the I&amp;middot;Cryo Kit

Here we demonstrate the newly developed I&#x2022;Cryo kit for mouse sperm cryopreservation. Two-cell stage embryo development with frozen-thawed sperm was improved consistently in 5 mouse strains with the use of this kit. Over a 1.5 year period, 49 genetically modified mouse lines were archived by sperm cryopreservation with the I&#x2022;Cryo kit and later successfully recovered by IVF.

Thousands of new genetically modified (GM) strains of mice have been created since the advent of transgenesis and knockout technologies.  Many of these ...

Generation of Human Induced Pluripotent Stem Cells from Peripheral Blood Using the STEMCCA Lentiviral Vector

Through the ectopic expression of four transcription factors, Oct4, Klf4, Sox2 and cMyc, human somatic cells can be converted to a pluripotent state, generating so-called induced pluripotent stem cells (iPSCs)1-4. Patient-specific iPSCs lack the ethical concerns that surround embryonic stem cells (ESCs) and would bypass possible immune rejection. Thus, iPSCs have attracted considerable attention for disease modeling studies, the screening of pharmacological compounds, and regenerative therapies5.
We have shown the generation of transgene-free human iPSCs from patients with different lung diseases using a single excisable polycistronic lentiviral Stem Cell Cassette (STEMCCA) encoding the Yamanaka factors6. These iPSC lines were generated from skin fibroblasts, the most common cell type used for reprogramming. Normally, obtaining fibroblasts requires a skin punch biopsy followed by expansion of the cells in culture for a few passages. Importantly, a number of groups have reported the reprogramming of human peripheral blood cells into iPSCs7-9. In one study, a Tet inducible version of the STEMCCA vector was employed9, which required the blood cells to be simultaneously infected with a constitutively active lentivirus encoding the reverse tetracycline transactivator. In contrast to fibroblasts, peripheral blood cells can be collected via minimally invasive procedures, greatly reducing the discomfort and distress of the patient. A simple and effective protocol for reprogramming blood cells using a constitutive single excisable vector may accelerate the application of iPSC technology by making it accessible to a broader research community. Furthermore, reprogramming of peripheral blood cells allows for the generation of iPSCs from individuals in which skin biopsies should be avoided (i.e. aberrant scarring) or due to pre-existing disease conditions preventing access to punch biopsies.
Here we demonstrate a protocol for the generation of human iPSCs from peripheral blood mononuclear cells (PBMCs) using a single floxed-excisable lentiviral vector constitutively expressing the 4 factors. Freshly collected or thawed PBMCs are expanded for 9 days as described10,11 in medium containing ascorbic acid, SCF, IGF-1, IL-3 and EPO before being transduced with the STEMCCA lentivirus. Cells are then plated onto MEFs and ESC-like colonies can be visualized two weeks after infection. Finally, selected clones are expanded and tested for the expression of the pluripotency markers SSEA-4, Tra-1-60 and Tra-1-81. This protocol is simple, robust and highly consistent, providing a reliable methodology for the generation of human iPSCs from readily accessible 4 ml of blood.

Here we show a simple and effective protocol for the generation of human iPSCs from 3-4 ml of peripheral blood using a single lentiviral reprogramming vector. Reprogramming of readily available blood cells promises to accelerate the utilization of iPSC technology by making it accessible to a broader research community.

Through the ectopic expression of four transcription factors, Oct4, Klf4, Sox2 and cMyc, human somatic cells can be converted to a pluripotent state, ...

Detection of Modified Forms of Cytosine Using Sensitive Immunohistochemistry

Methylation of cytosine bases (5-methylcytosine, 5mC) occurring in vertebrate genomes is usually associated with transcriptional silencing. 5-hydroxylmethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC) are the recently discovered modified cytosine bases produced by enzymatic oxidation of 5mC, whose biological functions remain relatively obscure. A number of approaches ranging from biochemical to antibody based techniques have been employed to study the genomic distribution and global content of these modifications in various biological systems. Although some of these approaches can be useful for quantitative assessment of these modified forms of 5mC, most of these methods do not provide any spatial information regarding the distribution of these DNA modifications in different cell types, required for correct understanding of their functional roles. Here we present a highly sensitive method for immunochemical detection of the modified forms of cytosine. This method permits co-detection of these epigenetic marks with protein lineage markers and can be employed to study their nuclear localization, thus, contributing to deciphering their potential biological roles in different experimental contexts.

Herein we describe a sensitive immunochemical method for mapping the spatial distribution of 5mC oxidation derivatives based on the use of peroxidase-conjugated secondary antibodies and tyramide signal amplification.

Methylation of cytosine bases (5-methylcytosine, 5mC) occurring in vertebrate genomes is usually associated with transcriptional silencing. ...

A Rapid Automated Protocol for Muscle Fiber Population Analysis in Rat Muscle Cross Sections Using Myosin Heavy Chain Immunohistochemistry

Quantification of muscle fiber populations provides a deeper insight into the effects of disease, trauma, and various other influences on skeletal muscle composition. Various time-consuming methods have traditionally been used to study fiber populations in many fields of research. However, recently developed immunohistochemical methods based on myosin heavy chain protein expression provide a quick alternative to identify multiple fiber types in a single section. Here, we present a rapid, reliable and reproducible protocol for improved staining quality, allowing automatic acquisition of whole cross sections and automatic quantification of fiber populations with ImageJ. For this purpose, embedded skeletal muscles are cut in cross sections, stained using myosin heavy chains antibodies with secondary fluorescent antibodies and DAPI for cell nuclei staining. Whole cross sections are then scanned automatically using a slide scanner to obtain high-resolution composite pictures of the entire specimen. Fiber population analyses are subsequently performed to quantify slow, intermediate and fast fibers using an automated macro for ImageJ. We have previously shown that this method can identify fiber populations reliably to a degree of &#177;4%. In addition, this method reduces inter-user variability and time per analyses significantly using the open source platform ImageJ.

Here, we present a protocol for rapid muscle fiber analyses, which allows improved staining quality, and thereby automatic acquisition and quantification of fiber populations using the freely available software ImageJ.

Quantification of muscle fiber populations provides a deeper insight into the effects of disease, trauma, and various other influences on skeletal muscle ...

Pancreatic Islet Embedding for Paraffin Sections

Experiments using isolated pancreatic islets are important for diabetes research, but islets are expensive and of limited abundance. Islets contain a mixed cell population in a structured architecture that impacts function, and human islets are widely variable in cell type composition. Current frequently used methods to study cultured islets include molecular studies performed on whole islets, lumping disparate islet cell types together, or microscopy or molecular studies on dispersed islet cells, disrupting islet architecture. For in vivo islet studies, paraffin-embedded pancreas sectioning is a powerful technique to assess cell-specific outcomes in the native pancreatic environment. Studying post-culture islets by paraffin sectioning would offer several advantages: detection of multiple outcomes on the same islets (potentially even the exact-same islets, using serial sections), cell-type-specific measurements, and maintaining native islet cell-cell and cell-substratum interactions both during experimental exposure and for analysis. However, existing techniques for embedding isolated islets post-culture are inefficient, time consuming, prone to loss of material, and generally produce sections with inadequate islet numbers to be useful for quantifying outcomes. Clinical pathology laboratory cell block preparation facilities are inaccessible and impractical for basic research laboratories. We have developed an improved, simplified bench-top method that generates sections with robust yield and distribution of islets. Fixed islets are resuspended in warm histological agarose gel and pipetted into a flat disc on a standard glass slide, such that the islets are distributed in a plane. After standard dehydration and embedding, multiple (10+) 4 - 5 &#181;m sections can be cut from the same islet block. Using this method, histological&#160;and immunofluorescent analyses can be performed on mouse, rat, and human islets. This is an effective, inexpensive, time-saving approach to assess cell-type-specific, intact-architecture outcomes from cultured islets.

Ex vivo pancreatic islet studies are important for diabetes research. Existing techniques to study cultured islets in their native 3-dimensional architecture are time consuming, inefficient, and infrequently used. This work describes a new, simple, and efficient method for generating high-quality paraffin sections of whole cultured islets.

Experiments using isolated pancreatic islets are important for diabetes research, but islets are expensive and of limited abundance. Islets contain a ...