drawing blood from C57 mice - (Jul/01/2009 )
Hi guys,
I'm pretty new to working with mice, because I only worked with rats and larger animals at the other lab that I worked at before. I have 2 different strains of mouse, the C57BL/6J (brown mice) and the ICR mouse (white mice). When my study director and I try to bleed the white mice by the tail vein, we can get a few drops of blood, which is what we wanted for our CardioChek analyzer to check the cholesterol. However, the C57 mice barely bleed at all. I am using the same size needle for both without a syringe-seems to collapse the vein with the syringe, which is usually a 26 gauge, the same warming procedure (by a heat lamp), but it just wasn't working. We ended up having to do a mandibular bleed, which to me, it seems a lot more stressful to the mouse. Does anyone have any tips for bleeding a mouse without anesthesizing the animal? Again, I'm not talking about large amounts of blood although if you have any ideas for that too, I'd appreciate it as well. Thanks.
Stacy 
Stace on Jul 1 2009, 05:29 PM said:
I'm pretty new to working with mice, because I only worked with rats and larger animals at the other lab that I worked at before. I have 2 different strains of mouse, the C57BL/6J (brown mice) and the ICR mouse (white mice). When my study director and I try to bleed the white mice by the tail vein, we can get a few drops of blood, which is what we wanted for our CardioChek analyzer to check the cholesterol. However, the C57 mice barely bleed at all. I am using the same size needle for both without a syringe-seems to collapse the vein with the syringe, which is usually a 26 gauge, the same warming procedure (by a heat lamp), but it just wasn't working. We ended up having to do a mandibular bleed, which to me, it seems a lot more stressful to the mouse. Does anyone have any tips for bleeding a mouse without anesthesizing the animal? Again, I'm not talking about large amounts of blood although if you have any ideas for that too, I'd appreciate it as well. Thanks.
Stacy
Firstly make sure that your "study director" has institutional and governmental approval for this study! Tail vein bleeding is one of the most basic methods in animal work. He/she should already have this "under their belt" if allowed to work with animals.
Like most methods, easy to show, hard to describe!
1. Gently warm cage with mice for 5 mins under an infrared lamp. If you place your hands under the lamp at "mouse level" for a minute it should be pleasantly warm, no hotter!
2. Gently put mouse into holder and pull the tail straight. Look for the lateral vein (one on each side of the tail!).
3. Quickly stab one of the veins with the sharp point of a scalpel (ca 2 cm from tip of tail)
4. Keep holding the tail straight. Wait until you get a drop of blood.
5. Take drop up into a pipetter + tip set at 20 ul.
6. As easy as that!
Work slowly and gently with your mice. Unfortunately we need them more than they need us!
Hope this helps.
Capillary pipette in the conjunctiva will get you a few drops.
GeorgeWolff on Jul 1 2009, 10:53 PM said:
true, and klinmed has given a good method of working too.
A little trick I used to do was, how strange it might sound, "massage" or give a few liltte, gentle taps on the tail, mouse before trying to take blood.
This has a positive effect on the blood flow.
Thanks for all of your help guys. I appreciate it.
Apart from tail vein, you may also try on the saphenous vein behind the hind leg. It allows you to collect 60-100 ul blood and works on BALB/c normal & nude mice (probably all mice). Our procedure is as follows:
1) Prepare a 50ml centrifuge tube & cut out the bottom to make an air passage.
2) Restrain the mice inside the tube with its head facing the bottom of the tube (grab hold on its tail all the time).
3) Gently pull the mice out a bit so that its leg (& hip) spread outside of the tube. The legs will straighten if you hold it right.
4) Remove the hair on the leg to reveal the saphenous vein.
5) Gently press on the leg/hip to make the vein more obvious.
6) Apply some vaseline on the leg (atop the vein).
7) Prepare a heparinize blood gas capillary tube (e.g 75 mm ext dia) & a microfuge tube for blood collection.
8) Use a needle (e.g 25G) to punch on the vein so that blood flow out as droplets
9) Quickly collect the blood using the capillary tube. Gently & repeatedly press & release the leg/hip to make blood continue to flow out.
10) Bleeding will stop naturally soon or you may apply some vaseline on the wound to quicken the stop.
11) Use a syringe (don't use mouth, I know somebody does!) with a tubing fitting to the capillary tube to blow out the blood into the microfuge tube.
12) Spin down at 3000 rpm for 10 min if you want plasma (optional).
If you need to collect blood everyday, try to do it on a different leg for consecutive days.
If you worry about the pain (to the mice), you may apply some pain killer before applying vaseline & needle punching. The vaseline helps the blood to form droplets so that its easier to be collected.
Hope this helps.