Adaptation of orbital bleeding technic to rapid serial blood studies

Summary Adaptation of orbital bleeding procedure to rapid, serial blood sampling of mice and other small laboratory animals has been made. Blood (0.2 ml) is collected in disposable, heparinized micropipettes by rupturing the fragile opthalmic venous plexus with tip of blood collection tube. The tube may be sealed and centrifuged for hematocrit determination and plasma separation for enzyme or other biochemical studies. Bleeding procedure for a mouse requires less than 30 seconds, and 100 mice can be bled and processed by a technician in about 1I/2 hours. Appropriate illustrations demonstrate technical details of procedure.