Hello, everybody, I'd like to ask you a question. E.G. 7-OVA cells were labeled with 5uM CFSE at 37℃ for 10 minutes and injected into mice via caudal vein. Why was it that CFSE-labeled cell signals in peripheral blood, spleen, and inguinal lymph nodes could not be detected by flow cytometry at 2.5 hours, 12 hours, and 16 hours after cell injection?

Thank you very mmuch.