IMR90 is a human fetal lung fibroblast cell line that has been modified to express mCherry, a red fluorescent protein. This cell line is useful for in vitro studies of cell biology, cell signaling, and drug discovery applications where fluorescence detection is required., These vials contain 1 million cells/mL of IMR90 cells expressing mCherry. The cells are cryopreserved for long-term storage and should be thawed according to standard cell culture protocols. Passage numbers are indicated for each vial to track cell line age.