Kapillærprøver

Kapillærprøver, also known as capillary action samples, refers to a method of collecting biological fluid samples using capillary tubes. This technique is commonly employed in medical diagnostics, particularly for obtaining small volumes of blood. Capillary tubes are narrow glass or plastic tubes that draw up a liquid by capillary action, a phenomenon where liquid molecules adhere to the tube walls and to each other, overcoming gravity.

The procedure typically involves pricking a patient's finger or heel to obtain a small blood droplet. This droplet is then touched to the open end of a capillary tube, allowing the blood to be drawn into the tube by capillary forces. Once filled, the ends of the capillary tube are often sealed, for example, with wax or a stopper, to prevent leakage and contamination.

Capillærprøver are advantageous for several reasons. They require only a minimal amount of sample, making them ideal for infants, young children, or situations where larger venipuncture is difficult or undesirable. The collection process is generally less invasive and quicker compared to traditional blood draws. Furthermore, the small volume of blood collected can be sufficient for various laboratory tests, including blood glucose monitoring, hemoglobin analysis, and certain serological tests.

The analysis of capillary samples often involves specialized equipment designed to handle these small volumes. Despite the convenience, it is important to note that capillary blood can sometimes differ slightly from venous blood in terms of its composition due to factors like tissue fluid dilution. Therefore, for certain critical diagnostic tests, venous blood samples may still be preferred.