1ML syringe with 22GA Needle
We use these to pull blood for Progesterone, pregnancy and Brucellosis tests. For one time use.
22Ga is the perfect compromise between painless stick and ease of drawing blood. And don't use a larger syringe, you will have a much harder time collecting. Needles can get blocked because of Hemolysis of blood.
1 mL is enough blood for all the tests we do.