IACUC

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PURPOSE:  

These guidelines have been developed to assist investigators and the IACUC in their choice and application of bleeding techniques to ensure that the techniques and procedures used will result in the least pain and distress to the animal, while adequately addressing the needs of the experimental design. 

POLICY:  

As with any procedure, training is critically important. The comfort and level of skill with a procedure, as well as the sample volume and frequency of sampling should be considered when choosing a method. Any exceptions to these guidelines must be scientifically justified in the Animal Care and Use Protocol and approved by the IACUC.

As a general rule, 1% of an animal's body weight (measured in grams) can be collected in blood (measured in milliliters) within a 24-hour period, every 14 days. For example, 0.3 ml can be collected once every two weeks from a 30-gram mouse. Alternatively, 0.05 ml of blood can be collected hourly for 6 consecutive hours from a 30-gram mouse, every two weeks (0.05 × 6 = 0.3 ml). Although blood volume is rapidly restored in an animal after blood collection, a two-week "rest period" is needed for blood constituents (red blood cells, platelets, clotting factors, etc.) to be regenerated by the body. 

If blood needs to be collected once a week, it is recommended that not more than 0.5% of the animal's body weight be removed within a 24-hour period. For example, 0.15 ml can be collected once a week from a 30-gram mouse. This volume can be further divided if blood needs to be collected more frequently. For example, 0.03 ml can be collected once a day for five days from a 30-gram mouse, provided the mouse is given a one week (or greater) "rest period" before blood is collected again. The key to determining how much and how frequently blood can be drawn depends on the "rest period" between blood collections. 

 

Acceptable Blood Sample Volume in ml's

Body weight

0.5%   once/week

1%   every 2 weeks

20 g

0.1

0.2

30 g

0.15

0.3

100 g

0.5

1.0

150 g

0.75

1.5 

200 g

1.0

2.0 

250 g

1.25

2.5 

300 g

1.5

3.0 

350 g

1.75

3.5

500 g

2.5

5.0

1 kg

5.0

10.0

2 kg

10.0

20.0

4 kg

20.0

40.0

 

Recommended Blood Collection Sites

SPECIE

SITE

ANESTHESIA

REPEATED BLEEDS?

EXPECTED VOLUME

Mouse

Saphenous vein

No

Yes

100-200 µ l

 

Submandibular vein

No

Yes

200-500 µ l

 

Lateral tail vein

No

Yes

50-100 µ l

Rat

Saphenous vein

No

Yes

300-400 µ l

 

Lateral tail vein

No

Yes

200-400 µ l

 

Jugular vein

Required

Yes

 0.5-2.0 ml

Ground Squirrel

Ventral tail artery

Required

Yes

0.5-2.0 ml

Rabbit

Marginal ear vein, central ear artery

Not required but sedation recommended

Yes

 

Ferret

Cephalic  vein

No

Yes

 

 

Saphenous vein

No

Yes

 

 

Jugular

Not required but sedation recommended

Yes

 

Other routes can be approved by the IACUC.

Terminal Blood Withdrawal

Terminal bleeds are only allowed on animals under general anesthesia, and the animal's death must be verified at the end of the bleed.  Cardiac puncture for blood collection may only be performed as a terminal event and the animal must be under general anesthesia .

A general rule: An animal's blood volume is 10 percent of its body weight, and only about half of that can be recovered when the animal is bled out. Therefore, as a terminal bleed, 5-6 percent of an animal's body weight is a reasonable amount of blood (ml) that can be collected at exsanguination.

 

Policy Adoption Date: 12/13/2012

Reference Minutes: 12/13/2012