Begin by placing PRDM in a water bath set at 37 degrees Celsius. Remove a cryovial containing day 32 hESC-derived photoreceptor progenitor cells from liquid nitrogen, and keep it on dry ice. Then thaw the cryovial in a water bath at 37 degrees Celsius for three to five minutes.
Re-suspend the cells in one milliliter of PRDM. Centrifuge them at 130G for four minutes After removing the supernatant, re-suspend the pellet in one milliliter of PRDM. To count the cells, take 10 microliters of the cell suspension and mix with 0.2%trypan blue, following the manufacturer's instructions.
Pipette the cell mixture into the cell counting chamber slide, and determine the cell number and viability using an automated cell counter. If cell viability is above 70%centrifuge the remaining cell suspension at 130G for four minutes. Remove the supernatant and re-suspend the cell pellet in PRDM for transplantation.
Using a 10 microliter pipette tip, re-suspend cell clumps in the microfuge tube until no clumps are visible. Load the suspension into a 33-gauge injection syringe and confirm the extrusion of cell solution through the needle.