Methodological diagram of in vivo temporal labeling of platelets in mice using fluorescently tagged antibodies. (A) Mice are injected with Dylight-x488–labeled anti-CD42c to achieve near universal labeling (>95%), followed by a second injection after 24 hours with Dylight-x649–labeled anti-CD42c results in a dual-labeled platelet population and a minority x649 single-label population corresponding to platelets generated in intervening 24-hour period since the first injection. (B) Representative pseudocolor dot plot of differentially labeled platelets from blood sample as detected by flow cytometry.