National Center for Competency Testing (NCCT) Medical Assistant Practice Test

What is the initial step when preparing a blood smear from a skin puncture?

1. Wipe away the first drop of blood

2. Collect the first drop for testing

3. Apply pressure to the puncture site

4. Disinfect the area with alcohol

The correct answer is: Wipe away the first drop of blood

The initial step when preparing a blood smear from a skin puncture is to wipe away the first drop of blood. This is crucial because the first drop may be contaminated with interstitial fluid, tissue cells, or debris, which can affect the quality and accuracy of the blood smear. By wiping it away, healthcare professionals ensure that the subsequent sample taken is more representative of whole blood and free from contaminants, leading to more reliable laboratory results. Additionally, this practice helps reduce the risk of introducing any pathogens or external contaminants into the sample. While collecting the first drop of blood is a common practice for some types of tests, in the context of preparing a blood smear, it is important to start with a clean sample. Applying pressure to the puncture site may facilitate blood flow but is not the first action when preparing the smear. Disinfecting the area with alcohol is important in the overall procedure, but it is typically done prior to making the puncture, rather than during the early preparation of the blood smear itself.