Which instrument is commonly used to pierce the skin for blood collection?

The lancet is specifically designed for making small incisions in the skin, which makes it ideal for blood collection, particularly in procedures like fingersticks. Its sharp, pointed edge allows for a precise puncture, minimizing discomfort while providing enough blood for testing. This instrument is often used in a clinical setting for obtaining small blood samples for glucose testing or other quick assessments.

Other instruments, while they have their own uses in medical practice, are not suitable for this particular task. A needle is typically used for drawing larger volumes of blood or for injections rather than for small skin punctures. A scalpel and a knife are intended for making larger incisions in surgical settings and are not appropriate or safe for the delicate task of skin puncturing specifically for blood collection. The design and function of a lancet make it the most suitable choice for this purpose.