Saphenous vein

Please read the general principles of blood sampling page before attempting any blood sampling procedure.

Technique

Sampling from the lateral saphenous vein is a relatively quick method of obtaining blood samples from hamsters. It does not require the animal to be warmed for sample collection.

Slides and videos of restraint and sampling for this technique are available on the websites of the Norwegian Reference Centre for Laboratory Animal Science and Alternatives and the University of Bergen.

Blood is collected from the lateral saphenous vein which runs dorsally and then laterally over the tarsal joint.   

Conscious hamsters should be restrained either manually or using a restraint tube. This can cause stress and therefore the duration of restraint should be minimised. Where a restraint tube is used, it should be appropriate for the size of the hamster. All forms of restraining equipment should be frequently washed to prevent pheromonally-induced stress or cross-infection.

To collect blood, the hind leg should be immobilised in the extended position by applying gentle downward pressure immediately above the knee joint. This stretches the skin over the ankle, making it easier to clip and immobilise the saphenous vein. Please note that hair removal by shaving with a scalpel blade is no longer recommended as it removes the epidermal layers of the skin. An aseptic technique should be used. Anaesthesia is not necessary but may be used on welfare grounds for animals that are difficult to hold. Where sedatives contain peripheral vasodilators, doses should be low to avoid prolonged bleeding from the puncture site. The number of attempts to take a blood sample should be minimised (no more than three needle sticks in any one attempt). Blood is collected by capillary action into a haematocrit tube or passively into a tube.

Blood flow can be stopped by gentle finger pressure over the puncture site, or simple relaxation of the operator's grip on the animal's leg. Animals should not be returned to their cage before the blood flow has stopped.

No more than four blood samples should be taken within any 24-hour period. If more samples are needed, then temporary or surgical cannulation should be considered. The scab or blood clot is removed for multiple samples.

Hamsters may show temporary favouring of the opposite limb following sampling from the saphenous vein.

Summary

Number of samples

No more than four blood samples should be taken within any 24-hour period.

Sample volume

Up to 0.15 ml for a single sample, which can usually be repeated at 2-week intervals without disturbances to haematological status. Alternatively, multiple smaller samples (e.g. 0.01 ml daily), taking into account limits on sample volume.

Equipment

27G or 25G needle or lance

Staff resource

One person is required to take the blood sample.

Adverse effects

  • Bruising
  • Haemorrhage
  • Infection
  • Temporary favouring of the opposite limb
 

Resources and references