Murine blood extraction technique - (Feb/04/2005 )
ANYONE GOT ANY IDEAS ON HOW TO EXTRACT BLOOD FROM MICE- I FIND CARDIAC PUNCTURE VERY HIT AND MISS?
you should try retro- orbital punction. it's easy to manage under anaesthesia
If you're doing a terminal proceedure, you may be able to get away with highly anesthetizing, opening the chest and then doing a cardiac puncture...like if going to do a perfusion. If the mice need to be saved for another day, retro-orbital could be done. I've also seen the nicking of a tail vein and collecting a small amount there.
Junie
It depends on how much blood you need. The total blood volume in an animal's body equals approximately 6% of its total body weight. To prevent anemia for nonterminal bleeds the guideline is you can take a volume of 1% of the body weight every two weeks. I have found that orbital sinus bleeding works very well in the mouse model.
Nicking the tail vein(s) with a sharp instrument like a scalpel gave me enough blood for monitoring antibody-titers, is non-terminal and I personally prefer a cut in the skin to drilling into the mouse's eye (<- dramatization! 
). The only thing you have to do for successful tail-blooding, is to make sure that the mouse is warmand therefor the peripheral vessels are wide - we use a redlight and put the mice under that 10 minutes before bleeding.
mike