A simple technique for blood collection in the opossum (Didelphis virginiana).

The left and right brachiocephalic veins were used for rapid collection of 5-10 ml blood samples in adult opossums. These vessels were also used to collect 0.5-1 ml blood samples in 120-day-old opossums. The animals were anaesthetized with 30 mg/kg of ketamine hydrochloride given intramuscularly prior to blood collection.