A simple technique for repeated blood collection from the tail vein of the rat.

A practical technique was described for collecting blood sample periodically from a conscious rat. Blood obtained from a tail vein, warmed for 10 seconds in water bath (at 50 degrees C), by inserting of a 22 G needle from which the adapter was cut off. Using this method, the influence of phlebotomy on hematologic parameters was determined. This technique was simple, easy, and reliable, and required no special skill and equipment.