Capillary Blood

Blood collected from capillary vessel is called capillary blood, the blood is usually collected by punting the fingertip of an adult using lancet while that of infant is collected from the heel or toe of the baby. The blood may be use for investigation differential count, enumeration of blood cells and hemoglobin estimation. But using of capillary blood for hematological examination has proven to have high risk of sample error, as such the use of capillary blood should discourage in the hematological investigation.  Repeat investigation is often restricted as a result of little quantity of collected blood. It is advisable to use capillary blood only when there is restriction of using venous blood for the investigation for example, burn case, new born baby, amputees, or in a case of a patient collection of venous blood is proven abortive.

Capillary Blood collection Technique

1. Select area suitable for puncture,
2. The ball of the middle finger is often proven to satisfactory. With 75% cotton wool soak with methylated spirit or alcohol, clean the selected area thoroughly and allow it to air dry, by doing that, it disinfected the selected area and aid circulation of blood.
3. Use disposable lancet and make quick stab on the selected area with application of little pressure simultaneously.
4. Used dry cotton wool clean the first drop of blood and then collected after that the one that will be used for the investigation.
5. When collecting using pipette e.g. Hemoglobin, RBC, or WBC pipette, apply a gentle suction via mouth of the end of the rubber tubing connected to pipette.
6. Blood should be draw exactly to the mark and make use that air bubble is avoided.
7. Clean the mouth of the pipette and delivered the blood into an appropriate diluent slowly
8. Mix the blood with the diluent to prevent coagulation. Type of Blood collecting Method