In which part of the body are capillary blood samples usually collected from infants?

Capillary blood samples in infants are typically collected from the heel due to the ease and safety this method provides. The heel is an appropriate site because it is less prone to injury compared to other areas and is well supplied with blood vessels, making it a reliable location for obtaining a small volume of blood. This method is particularly useful for infants who have small veins that can be challenging to access.

Other areas mentioned, such as the thumb, index finger, and earlobe, are generally not recommended for capillary sampling in infants. The thumb and index finger are better suited for older children and adults, as they may not provide adequate blood flow in infants. The earlobe, while sometimes used in adults, does not have the same accessibility and may cause discomfort to infants. Thus, the heel remains the preferred choice for this procedure.