Capillary Tubes

Capillary blood collection plays an important role not only in paediatrics but across all healthcare disciplines. It is used for all laboratory analyses that require smaller blood volumes and, unlike arterial blood collection, which is highly invasive, is considerably gentler on the patient’s skin.

The procedure is typically performed on the lateral fingertip, earlobe, or in small children and infants, often on the heel. These areas are well-perfused and contain numerous capillaries. Using a sterile lancet, the tiny blood vessels are punctured to allow blood to flow from the site. The blood is then collected with a capillary tube appropriate for the test and subsequently analysed.

Capillary tubes are used to determine the volume fraction of erythrocytes in the blood and can, for example, be centrifuged in a suitable haematocrit centrifuge such as the iFuge HCT NXT. You can also find the necessary Haematocrit Sealing Kit, 1 piece from Karl Hecht for sealing the glass capillaries in this category. By separating the individual blood components in the capillary tube and using appropriate HKT evaluation charts, the proportion of red blood cells in patient samples can be accurately measured.

The capillary blood collection systems from Sarstedt provide a simple and reliable way to collect and store capillary blood. The capillaries are available with different preparations for various blood analysis procedures. For example, the Microvette® 200, featuring an end-to-end design for collecting 200 µl of capillary blood, is available in glucose, haematology, and serum variants. The system from this reputable manufacturer stands out for its functional and well-thought-out design. Due to the specially engineered lid, a secure and audible closure is ensured, while opening the Microvette® collection systems produces a reduced aerosol effect. Additionally, they feature a physical mixing aid to ensure uniform mixing of the blood sample with the corresponding reagent.