Capillary collection tubes are designed to collect blood from a fingerstick. Which option reflects this use?

• A. Venipuncture
• B. Fingerstick
• C. Arterial puncture
• D. Central line

Answer: (B)

Capillary collection tubes are designed to collect blood from a fingerstick. This method is ideal when only a small volume is needed, such as for point-of-care tests or in patients where venous access is challenging. Blood is drawn into the tube by capillary action from a shallow finger puncture, typically after warming the site, cleaning it, and wiping away the first drop to avoid tissue-fluid contamination. Avoid squeezing the finger, which can dilute the sample with interstitial fluid, and collect until the required volume is reached. The other methods draw blood from veins, arteries, or central lines and require different techniques and tubes, so they don’t reflect the intended use of capillary collection tubes.