To perform fluorescence-activated cell sorting, or FACS, on the gut cells isolated from zebrafish larvae, use the wild-type whole larvae sample to set the gates of the sorted cell population by recording 3, 000 cells on the flow cytometer. Use a 100-micron nozzle and set Sort Precision to 4-Way Purity. Put the collection tube containing 200 microliters of PBS with 5%fetal calf serum in the fax machine.
Load the cell suspension prepared from the isolated guts, and after excluding doublets in dead cells, sort live or DAPI-negative single cells into the collection tube. Keep the collection tube on ice after cell sorting, employing a viability check with trypan blue. Count the number of cells in the suspension with a hemocytometer.
The cells are now ready to be processed for single-cell RNA sequencing. Use approximately 20, 000 cells per sample.