Induction of Adoptive DTH
Please see JoVE article: <a href="https://www.jove.com/video/325">Induction and Monitoring of Adoptive Delayed-Type Hypersensitivity in Rats</a> Christine Beeton, George K. Chandy Department of Physiology and Biophysics, University of California, Irvine J. Visualized Experiments, Issue 8
Here, we have modified this protocol by using antigen (Ovalbumin) conjugated to Texas-Red in a 1:1 ratio with unlabeled antigen to allow for visualization of phagocytic antigen-presenting cells.
Ear Tissue Harvest
<ol>
<li>Euthanize the rat at the desired time-point by procedures outlined in your approved animal protocol. Here, we use an overdose of the anesthetic, isoflurane. This is done in a closed container located inside a well-ventilated hood. Ensure the animal is dead by either decapitation of by opening the thoracic cavity and cutting the heart. </li>
<li>Using large scissors remove the ear with a single cut, as close to the body of the animal as possible (Figure 1). <img src="/files/ftp_upload/old/907_2008_8_13_0/Figure_1.jpg" alt="Figure_1.jpg" /> Figure 1. Removal of the rat ear </li>
<li>Place the ear in a 15 ml conical tube containing ~10 ml of ice-cold 1x PBS or RPMI-1640. Keep the tissue samples on ice until you are ready to prepare the tissue for imaging. </li>
<li>Image the tissue as soon as possible; we find, though,&nbsp;that 1 to 2 hours on ice has no discernable effect on cell motility in the tissue when compared to tissue harvested and imaged immediately.</li>
</ol>
Tissue Preparation for Imaging
I. Removal of Epidermal and Dermal Layer
*Note: The deep dermal layer must be kept intact. If done correctly large blood vessels will remain intact and the cartilage of the ear will not be exposed. This is a difficult technique, especially when there is no inflammation (control conditions) and it is helpful to use a dissecting microscope.
<ol>
<li>Place both the tissue and media from the conical tube in a 10 cm tissue culture dish. </li>
<li>With gloved hands hold the rat ear gently at the tip of the ear (distal) with the dorsal side of the ear facing up (Figure 2). <img src="/files/ftp_upload/old/907_2008_8_13_1/Figure_2.jpg" alt="Figure_2.jpg" /> Figure 2. Trim fur off the ear </li>
<li>With your thumb on top of the ear, steady the tissue while using the tip of closed Dumont #5 scissors to separate the dermis from the deep dermis. Alternatively, if the edge of the ear has an overhang of skin/deep dermis, this can be grasped with forceps and gently pulled to separate this from the tissue underneath (Figure 3). <img src="/files/ftp_upload/old/907_2008_8_13_2/Figure_3.jpg" alt="Figure_3.jpg" /> Figure 3. Removal of the upper dermis </li>
<li>Once a small area of skin has been separated from the underlying tissue, repeat the separation steps alternatively using scissors to cut between the dermal layers and forceps to gently remove and peel off the dislodged skin. </li>
<li>Expose a 5 x 5 mm or larger area of ear tissue that is at least 3 mm from the initial site of antigen injection (Figure 4). <img src="/files/ftp_upload/old/907_2008_8_13_3/Figure_4.jpg" alt="Figure_4.jpg" /> Figure 4. Tissue exposed for imaging </li>
</ol>
II. Securing Tissue to the Imaging Stage
<ol>
<li>Cut a plastic cover slip to a size slightly larger than prepared tissue. </li>
<li>Spread a thin layer of 3M Vetbond&trade; tissue-safe glue across the slide. </li>
<li>Grasp the corner of the prepared tissue (where you are not likely to image), remove from media, and dab the underside of the tissue on lens paper or Kym wipe to remove excess media. </li>
<li>Touch the edge of the tissue to the glue covered slide (the Vetbond cures immediately on wet tissue). Gently stretch the tissue flat, with the opposite end being the last to touch the slide (Figure 5) <img src="/files/ftp_upload/old/907_2008_8_13_4/Figure_5.jpg" alt="Figure_5.jpg" /> Figure 5. Mount tissue to cover slip </li>
<li>Cure the Vetbond&trade; by inverting the tissue sample/slide and dipping it in a reservoir of media such that the tissue and slide are face down and roughly at a 45 degree angle. Holding the tissue upside down at an angle helps to prevent excess glue from curing on the exposed tissue surface. Glue on the surface of the tissue will block the laser (Figure 6). <img src="/files/ftp_upload/old/907_2008_8_13_5/Figure_6.jpg" alt="Figure_6.jpg" /> Figure 6. Cure vetbond tissue glue by dipping in media Note: Steps 2-5 may take a little practice to master. Try practicing with discarded or extra tissue pieces before attempting for the first time. </li>
<li>Dab a small amount of silicone grease onto the bottom of the slide. </li>
<li>Place the slide in the perfusion chamber. Make sure that the perfusion media is flowing, 37&deg;C and oxygenated before adding tissue. Gently press down on the edges of the slide making a seal with the silicon grease between the bottom of the perfusion chamber and the plastic cover slip. </li>
</ol>
III. Two-Photon Imaging
<ol>
<li>Using bright-field transmitted light, focus on the top of the tissue. Turn off all of lights. </li>
<li>Turn on the laser, PMTs as required by your multi-photon microscope system. </li>
<li>Second harmonic generation (SHG) in highly-ordered fibrous proteins (collagen and myosin) produces a signal at half the wavelength of the excitation laser. We use excitation at 900 nM, leading to SHG at 450 nm which can be visualized using the "blue" channel of the microscope. SHG generation is a non-linear (two-photon) process, and thus provides an optical "sectioning" effect similar to that of two-photon excitation of fluorescence. The peak efficiency of SHG occurs when the fibrils are perpendicular to the laser, while fibrils that run in parallel will not be visualized.1 </li>
<li>Locate a good imaging area with plenty of cells, set your acquisition area such that the majority of cells are in the center and start imaging. Note: In DTH reactions, T cells and other cell infiltrates are often found to be concentrated together while other areas are devoid of infiltrating cells2. Therefore, it may take some time searching the tissue to find the best area to image. </li>
<li>Check for cell viability by assessing cell velocity and polarity during imaging. Use the lowest laser power that provides acceptable image quality to ensure minimal photo-damage. </li>
<li>Swap in a new tissue preparation as needed.</li>
</ol>

<ol>
	<li>Koo, G. C., 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=Blockade+of+the+voltage-gated+potassium+channel+Kv1.3+inhibits+immune+responses+in+vivo.">Blockade of the voltage-gated potassium channel Kv1.3 inhibits immune responses in vivo.</a> J Immunol. 158, 5120-5128 (1997).</li><li>Gaga, M., Frew, A. J., Varney, V. A., Kay, A. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Eosinophil+activation+and+T+lymphocyte+infiltration+in+allergen-induced+late+phase+skin+reactions+and+classical+delayed-type+hypersensitivity.">Eosinophil activation and T lymphocyte infiltration in allergen-induced late phase skin reactions and classical delayed-type hypersensitivity.</a> J Immunol. 147, 816-822 (1991).</li><li>Flugel, A., Odoardi, F., Nosov, M., Kawakami, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autoaggressive+effector+T+cells+in+the+course+of+experimental+autoimmune+encephalomyelitis+visualized+in+the+light+of+two-photon+microscopy.">Autoaggressive effector T cells in the course of experimental autoimmune encephalomyelitis visualized in the light of two-photon microscopy.</a> J Neuroimmunol. 191, 86-97 (2007).</li><li>Kawakami, N., 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=Live+imaging+of+effector+cell+trafficking+and+autoantigen+recognition+within+the+unfolding+autoimmune+encephalomyelitis+lesion.">Live imaging of effector cell trafficking and autoantigen recognition within the unfolding autoimmune encephalomyelitis lesion.</a> J Exp Med. 201, 1805-1814 (2005).</li><li>Miller, M. J., Wei, S. H., Parker, I., Cahalan, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two-photon+imaging+of+lymphocyte+motility+and+antigen+response+in+intact+lymph+node.">Two-photon imaging of lymphocyte motility and antigen response in intact lymph node.</a> Science. 296, 1869-1873 (2002).</li><li>Matheu, M. P. B., A, C. G. a. r. c. i. a., Chi, V., Rangaraju, S., Safrina, O., Monaghan, K., Uemura, M. I., Li, D., Pal, S., Monuki, E., Flugel, A., Pennington, M. W., Parker, I., Chandy, G. K., Calahan, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+Situ+Imaging+of+Effector/Memory+T+Cells+During+DTH+and+Suppression+by+Kv1.3+Channel+Block.">In Situ Imaging of Effector/Memory T Cells During DTH and Suppression by Kv1.3 Channel Block.</a> Immunity. , (2008).</li></ol>

imaging effector memory t cells in the ear after induction of adoptive dth

Delayed type hypersensitivity (DTH) is an immune reaction in which the main players are CCR7- effector / memory T lymphocytes. Here, we demonstrate a method for inducing and recording the progress of a DTH reaction in the rat ear. This is followed by a demonstration of the preparation of rat ear tissue for two-photon imaging of the CCR7- effector / memory T cell response.
An adoptive DTH is induced by the intraperitoneal injection of GFP-labeled Ova-specific CCR7- effector / memory T cell line (Beeton, C J. Visualized Experiments, Issue 8). Cells are then allowed to equilibrate in the rat for 48 hours before challenge by injecting one ear with saline (control ear) and the other with a 1:1 mix of Ova and Ova conjugated to Texas-Red (Ova-TR) to allow visualization of resident antigen-presenting cells.
We describe a method of tissue preparation useful for imaging the motility of cells within the deep dermal layer during an immune response, in conjunction with visualization of collagen fibers by second harmonic generation. Ear tissue is cut into 5 x 5 mm squares (slightly larger is better) and mounted onto plastic cover slips using Vetbond&trade;, which are then secured using silicone grease in an imaging chamber and superfused by oxygen-bubbled tissue culture medium at 37&deg;C.

Watch this Scientific Journal Video about Imaging Effector Memory T cells in the Ear After Induction of Adoptive DTH at JoVE.com

Imaging Effector Memory T cells in the Ear After Induction of Adoptive DTH

Here we demonstrate a method for inducing and recording the progress of a delayed type-hypersensitivity (DTH) reaction in the rat ear. This is followed by a demonstration of the preparation of rat ear tissue for two-photon imaging of the effector / memory T cell response.

Delayed type hypersensitivity (DTH) is an immune reaction in which the main players are CCR7- effector / memory T lymphocytes. Here, we demonstrate a ...

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10.2K Views.  University of California, Irvine (UCI). Here we demonstrate a method for inducing and recording the progress of a delayed type-hypersensitivity (DTH) reaction in the rat ear. This is followed by a demonstration of the preparation of rat ear tissue for two-photon imaging of the effector / memory T cell response.

Video: Imaging Effector Memory T cells in the Ear After Induction of Adoptive DTH

Induction and Monitoring of Active Delayed Type Hypersensitivity (DTH) in Rats

Delayed type hypersensitivity (DTH) is an inflammatory reaction mediated by CCR7- effector memory T lymphocytes that infiltrate the site of injection of an antigen against which the immune system has been primed. The inflammatory reaction is characterized by redness and swelling of the site of antigenic challenge. It is a convenient model to determine the in vivo efficacy of immunosuppressants. Cutaneous DTH can be induced either by adoptive transfer of antigen-specific T lymphocytes or by active immunization with an antigen, and subsequent intradermal challenge with the antigen to induce the inflammatory reaction in a given skin area. DTH responses can be induced to various antigens, for example ovalbumin, tuberculin, tetanus toxoid, or keyhole limpet hemocyanin (KLH).
Here we demonstrate how to induce an active DTH reaction in Lewis rats. We will first prepare a water-in-oil emulsion of KLH, our antigen of interest, in complete Freund's adjuvant and inject this emulsion subcutaneously to rats. This will prime the immune system to develop memory T cells directed to KLH. Seven days later we will challenge the rats intradermally on the back with KLH on one side and with ovalbumin, an irrelevant antigen, on the other side. The inflammatory reaction will be visible 16-72 hours later and the red and swollen area will be measured as an indication of DTH severity.

Induction and Monitoring of Active Delayed Type Hypersensitivity DTH in Rats

Delayed type hypersensitivity (DTH) is an inflammatory reaction mediated by CCR7- effector memory T lymphocytes. Here we demonstrate how to induce active DTH in Lewis rats and monitor the inflammatory response.

Delayed type hypersensitivity (DTH) is an inflammatory reaction mediated by CCR7- effector memory T lymphocytes that infiltrate the site of injection of ...

Induction and Monitoring of Adoptive Delayed-Type Hypersensitivity in Rats

Delayed type hypersensitivity (DTH) is an inflammatory reaction mediated by CCR7- effector memory T lymphocytes that infiltrate the site of injection of an antigen against which the immune system has been primed. The inflammatory reaction is characterized by redness and swelling of the site of antigenic challenge. It is a convenient model to determine the in vivo efficacy of immunosuppressants. Cutaneous DTH can be induced either by adoptive transfer of antigen-specific T lymphocytes or by active immunization with an antigen, and subsequent intradermal challenge with the antigen to induce the inflammatory reaction in a given skin area. DTH responses can be induced to various antigens, for example ovalbumin, tuberculin, tetanus toxoid, or keyhole limpet hemocyanin. Such reactions can also be induced against autoantigen, for example to myelin basic protein (MBP) in rats with experimental autoimmune encephalomyelitis induced with MBP, an animal model for multiple sclerosis (1).
Here we demonstrate how to induce an adoptive DTH reaction in Lewis rats. We will first stimulate ovalbumin-specific T cells in vitro and inject these activated cells intraperitoneally to naive rats. After allowing the cells to equilibrate in vivo for 2 days, we will challenge the rats with ovalbumin in the pinna of one ear, while the other ear wil receive saline. The inflammatory reaction will be visible 3-72 hours later and ear thickness will be measured as an indication of DTH severity.

Delayed type hypersensitivity (DTH) is an inflammatory reaction mediated by CCR7- effector memory T (TEM) lymphocytes. Here we demonstrate how to activate antigen-specific TEM cells, induce adoptive DTH in Lewis rats and monitor the inflammatory response.

Clonogenic Assay: Adherent Cells

The clonogenic (or colony forming) assay has been established for more than 50 years; the original paper describing the technique was published in 19561. Apart from documenting the method, the initial landmark study generated the first radiation-dose response curve for X-ray irradiated mammalian (HeLa) cells in culture1. Basically, the clonogenic assay enables an assessment of the differences in reproductive viability (capacity of cells to produce progeny; i.e. a single cell to form a colony of 50 or more cells) between control untreated cells and cells that have undergone various treatments such as exposure to ionising radiation, various chemical compounds (e.g. cytotoxic agents) or in other cases genetic manipulation. The assay has become the most widely accepted technique in radiation biology and has been widely used for evaluating the radiation sensitivity of different cell lines. Further, the clonogenic assay is commonly used for monitoring the efficacy of radiation modifying compounds and for determining the effects of cytotoxic agents and other anti-cancer therapeutics on colony forming ability, in different cell lines. A typical clonogenic survival experiment using adherent cells lines involves three distinct components, 1) treatment of the cell monolayer in tissue culture flasks, 2) preparation of single cell suspensions and plating an appropriate number of cells in petri dishes and 3) fixing and staining colonies following a relevant incubation period, which could range from 1-3 weeks, depending on the cell line. Here we demonstrate the general procedure for performing the clonogenic assay with adherent cell lines with the use of an immortalized human keratinocyte cell line (FEP-1811)2. Also, our aims are to describe common features of clonogenic assays including calculation of the plating efficiency and survival fractions after exposure of cells to radiation, and to exemplify modification of radiation-response with the use of a natural antioxidant formulation.

The applicability of the clonogenic assay for evaluating reproductive viability has been established for more than 50 years. Here we demonstrate the general procedure for performing the clonogenic assay with adherent cells.

The clonogenic (or colony forming) assay has been established for more than 50 years; the original paper describing the technique was published in 19561. ...

Imaging of Estrogen Receptor-&alpha; in Rat Pial Arterioles using a Digital Immunofluorescent Microscope

Many of estrogen's effects on vascular reactivity are mediated through interaction with estrogen receptors 1, 2, 3. Although two sub-types exist (estrogen receptor -&alpha; and &beta;),estrogen receptor-&alpha; has been identified in both the smooth muscle and in endothelial cells of pial arterial segments using fluorescent staining combined with confocal laser scanning microscopy 4. Furthermore, ER-&alpha; is located in the nuclei and in the cytoplasm of rat basilar arteries 5. The receptors are abundant and fluoresce brightly, but clear visualization of discrete groups of receptors is difficult likely due to the numbers located in many cell layers of pial vessel segments. Additionally, many reports using immunohistochemical techniques paired with confocal microscopy poorly detail the requirements critical for reproduction of experiments 6. Our purpose for this article is to describe a simple technique to optimize the staining and visualization of ER-&alpha; using cross-sectional slices of pial arterioles obtain from female rat brains. We first perfuse rats with Evans blue dye to easily identify surface pial arteries which we isolate under a dissecting microscope. Use of a cryostat to slice 8 &mu;m cross sections of the arteries allows us to obtain thin vessel sections so that different vessel planes are more clearly visualized. Cutting across the vessel rather than use of a small vessel segment has the advantage of easier viewing of the endothelial and smooth muscle layers. In addition, use of a digital immunofluorescent microscope with extended depth software produces clear images of ten to twelve different vessel planes and is less costly than use of a confocal laser scanning microscope.

Imaging of Estrogen Receptor-&amp;#945; in Rat Pial Arterioles using a Digital Immunofluorescent Microscope

The goal of this article is to demonstrate a method to optimize immunofluorescent detection of estrogen receptor-&#945; (ER&#945;) in rat pial arterial slices using a digital immunofluorescent microscope.

Many of estrogen's effects on vascular reactivity are mediated through interaction with estrogen receptors 1, 2, 3. Although two sub-types exist (estrogen ...

Induction and Analysis of Epithelial to Mesenchymal Transition

Epithelial to mesenchymal transition (EMT) is essential for proper morphogenesis during development. Misregulation of this process has been implicated as a key event in fibrosis and the progression of carcinomas to a metastatic state. Understanding the processes that underlie EMT is imperative for the early diagnosis and clinical control of these disease states. Reliable induction of EMT in vitro is a useful tool for drug discovery as well as to identify common gene expression signatures for diagnostic purposes. Here we demonstrate a straightforward method for the induction of EMT in a variety of cell types. Methods for the analysis of cells pre- and post-EMT induction by immunocytochemistry are also included. Additionally, we demonstrate the effectiveness of this method through antibody-based array analysis and migration/invasion assays.

A straightforward method is described for the induction of epithelial to mesenchymal transition (EMT) in a variety of cell types. Methods for the analysis of cells in EMT states by immunocytochemistry are included.

Epithelial  to mesenchymal transition (EMT) is essential for proper morphogenesis during  development. Misregulation of this  process has been implicated ...

Imaging Local Ca2+ Signals in Cultured Mammalian Cells

Cytosolic Ca2+ ions regulate numerous aspects of cellular activity in almost all cell types, controlling processes as wide-ranging as gene transcription, electrical excitability and cell proliferation. The diversity and specificity of Ca2+ signaling derives from mechanisms by which Ca2+ signals are generated to act over different time and spatial scales, ranging from cell-wide oscillations and waves occurring over the periods of minutes to local transient Ca2+ microdomains (Ca2+ puffs) lasting milliseconds. Recent advances in electron multiplied CCD (EMCCD) cameras now allow for imaging of local Ca2+ signals with a 128 x 128 pixel spatial resolution at rates of &#62;500 frames sec-1 (fps). This approach is highly parallel and enables the simultaneous monitoring of hundreds of channels or puff sites in a single experiment. However, the vast amounts of data generated (ca. 1 Gb per min) render visual identification and analysis of local Ca2+ events impracticable. Here we describe and demonstrate the procedures for the acquisition, detection, and analysis of local IP3-mediated Ca2+ signals in intact mammalian cells loaded with Ca2+ indicators using both wide-field epi-fluorescence (WF) and total internal reflection fluorescence (TIRF) microscopy. Furthermore, we describe an algorithm developed within the open-source software environment Python that automates the identification and analysis of these local Ca2+ signals. The algorithm localizes sites of Ca2+ release with sub-pixel resolution; allows user review of data; and outputs time sequences of fluorescence ratio signals together with amplitude and kinetic data in an Excel-compatible table.

Imaging Local Ca2+ Signals in Cultured Mammalian Cells

Here we present techniques for imaging local IP3-mediated Ca2+ events using fluorescence microscopy in intact mammalian cells loaded with Ca2+ indicators together with an algorithm that automates identification and analysis of these events.

Cytosolic Ca2+ ions regulate numerous aspects of cellular activity in almost all cell types, controlling processes as wide-ranging as gene transcription, ...

High-resolution Time-lapse Imaging and Automated Analysis of Microtubule Dynamics in Living Human Umbilical Vein Endothelial Cells

The physiological process by which new vasculature forms from existing vasculature requires specific signaling events that trigger morphological changes within individual endothelial cells (ECs). These processes are critical for homeostatic maintenance such as wound healing, and are also crucial in promoting tumor growth and metastasis. EC morphology is defined by the organization of the cytoskeleton, a tightly regulated system of actin and microtubule (MT) dynamics that is known to control EC branching, polarity and directional migration, essential components of angiogenesis. To study MT dynamics, we used high-resolution fluorescence microscopy coupled with computational image analysis of fluorescently-labeled MT plus-ends to investigate MT growth dynamics and the regulation of EC branching morphology and directional migration. Time-lapse imaging of living Human Umbilical Vein Endothelial Cells (HUVECs) was performed following transfection with fluorescently-labeled MT End Binding protein 3 (EB3) and Mitotic Centromere Associated Kinesin (MCAK)-specific cDNA constructs to evaluate effects on MT dynamics. PlusTipTracker software was used to track EB3-labeled MT plus ends in order to measure MT growth speeds and MT growth lifetimes in time-lapse images. This methodology allows for the study of MT dynamics and the identification of how localized regulation of MT dynamics within sub-cellular regions contributes to the angiogenic processes of EC branching and migration.

Protocols for Human Umbilical Vein Endothelial Cell (HUVEC) culture, transient transfection of fluorescently-labeled markers of microtubule growth, live-cell imaging and automated analysis of interphase microtubule growth dynamics are detailed.

The physiological process by which new vasculature forms from existing vasculature requires specific signaling events that trigger morphological changes ...

A Graphical User Interface for Software-assisted Tracking of Protein Concentration in Dynamic Cellular Protrusions

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We present a software solution for semi-automated tracking of relative protein concentration along the length of dynamic cellular protrusions.

Filopodia are dynamic, finger-like cellular protrusions associated with migration and cell-cell communication. In order to better understand the complex ...

Fluorescence Recovery after Photobleaching of Yellow Fluorescent Protein Tagged p62 in Aggresome-like Induced Structures

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We describe a comprehensive and practical protocol for fluorescence recovery after photobleaching experiments with live cells. Although the protocol was used to measure the mobility of yellow fluorescent protein-tagged p62 in aggresome-like induced structures, it can be applied to a variety of microscopy systems and fluorescent proteins.

Fluorescence recovery after photobleaching (FRAP)&#160;is a microscopy technique that can be used to quantify protein mobility in live cells. In a typical ...

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This protocol, which was originally reported by Fernandez-Godino et al. in 20161, describes a method to efficiently isolate and culture mouse RPE cells, which form a functional and polarized RPE monolayer within one week on Transwell plates. The procedure takes approximately 3 hours.

Eye disorders affect millions of people worldwide, but the limited availability of human tissues hinders their study. Mouse models are powerful tools to ...