Common marmosets are intelligent and can be trained to cooperate with blood sampling thus reducing the stress caused. They will remember receiving a reward (e.g. food treat) after the procedure, which can make them easier to handle during subsequent procedures.

Sampling from the femoral vein is the most commonly used route in the marmoset. The vein is not usually visible and stemming blood flow can be slow. The femoral triangle is prone to bruising. Analgesia can be used if necessary.

The technique should be carried out aseptically. Where multiple samples are taken alternate legs should be used. 0.1 - 3 ml of blood can be obtained per sample and, depending on sample volume, usually no more than seven samples in a 24-hour period. The number of attempts to take a blood sample should be minimised (no more than three needle sticks in any one attempt) and the femoral triangle should be allowed to recover before the next blood sampling session. Finger pressure on cotton wool should be applied to the site until bleeding stops, after which the marmoset can be returned to its cage.

Catching and restraining a marmoset can cause it stress, especially for repeated sampling. Training the animal to enter a restraining box or cage turret may reduce the stress of capture. The duration of restraint should be kept to a minimum. Good preparation of the area where the sampling will take place will help to minimise the time taken to complete the procedure. 

Number of samples:

No more than seven blood samples should be taken in any 24-hour period.

Sample volume:

0.1 - 3 ml

Equipment:

25G needle

Staff resource:

Two people are required: one to take the blood sample and another to restrain the marmoset.

Adverse effects :

Haematoma if blood flow is not stopped.

Other:

The femoral triangle is prone to bruising and stopping the blood flow can be slow.