Question on Vet techniques and drawing blood from Crotalids.

[ChurleR]

Hello, I'm new to this forum and I have a few questions on vet techniques for Crotalids. I'm working with an entomologist in my Bio department and he chose me because I seem to be one of the only people experienced with hots. I'm decent at tubing and getting snakes prepped for vet care but I really need to know where to draw blood from. Is it a matter of personal preference or not? I realize that usually blood is drawn from inbetween two ventral scales, and I know about the anatomical differences between viperids and elapids/colubrids (ie heart placement). I just don't know where to aim or what type of needle to use. Any input would be much appreciated, and rest assured I'm not going to attempt to draw blood from any snakes before I know exactly what I'm doing. I refuse to injure or kill a snake due to my lack of knowledge.

-Will