American Society for Clinical Pathology (ASCP) Histotechnician Certification Practice Exam

Which of the following laboratory procedures involves the use of a serum separator tube?

1. Microbial culture

2. Serum chemistry analysis

3. Hematocrit measurement

4. Coagulation testing

The correct answer is: Serum chemistry analysis

The use of a serum separator tube is specifically designed for procedures where serum is required for analysis, making it ideal for serum chemistry analysis. This type of tube contains a gel that separates the serum from the cellular components of blood after centrifugation, allowing for the collection of clear serum for various biochemical tests. Serum chemistry analysis relies on testing the liquid portion of blood to measure levels of various substances, such as proteins, enzymes, hormones, and electrolytes. The distinct feature of serum separator tubes is their ability to facilitate the collection of serum in a streamlined manner, ensuring that the serum is free from any cellular debris or clotting factors, which could interfere with the analysis. In contrast, microbial culture, hematocrit measurement, and coagulation testing do not typically employ serum separator tubes. Microbial culture often uses different culture media that can support the growth of microorganisms. Hematocrit measurement evaluates the proportion of blood volume occupied by red blood cells and usually requires whole blood samples. Coagulation testing assesses blood clotting dynamics typically using specialized tubes designed to prevent coagulation, rather than separating serum. Thus, serum chemistry analysis stands out as the correct context for the use of serum separator tubes.