ASCP Capillary Puncture and Dermal Collection

Question 1

Which finger is the preferred site for capillary blood collection in adults?

Accepted Answer

Middle or ring finger

Answer

The middle and ring fingers are preferred because they have more tissue depth and are less calloused than the thumb or index finger.

Question 2

What is the purpose of discarding the first drop of blood during capillary collection?

Accepted Answer

It may be contaminated with tissue fluid that can cause erroneous results

Answer

The first drop may be diluted with tissue fluid released during the puncture, which can affect test results.

Question 3

Which area of the heel is recommended for capillary puncture in neonates?

Accepted Answer

The medial or lateral plantar surface

Answer

The medial or lateral plantar surface avoids the calcaneus bone and major nerves and arteries, making it the safe zone for heel sticks.

Question 4

What is the maximum recommended puncture depth for a neonate heel stick per CLSI guidelines?

Accepted Answer

2.0 mm

Answer

CLSI guidelines recommend a maximum puncture depth of 2.0 mm for neonatal heel sticks to avoid hitting the calcaneus bone.

Question 5

In capillary blood collection, which specimen is collected FIRST when multiple collection devices are used?

Accepted Answer

EDTA (lavender) tubes

Answer

In capillary collection, EDTA tubes are collected first to ensure adequate anticoagulation before platelets begin to aggregate.

ASCP Phlebotomy Technician Exam Practice Test