blood sampling

Laboratory examination of samples of blood. These are usually collected from an appropriate vein, but arterial samples are required for some special techniques. Collection is by a closed method, either a hypodermic syringe or a vacuumized container. The site of collection varies with the species and the circumstances. The sample may be clotted, for serum estimations, or collected with an anticoagulant for examinations on plasma or whole blood.