Veterinary Technician Practice Exam

Which blood collection tube is sterile and primarily used for hematology studies?

1. Red top tube

2. Green top tube

3. Lavender top tube

4. Blue top tube

The correct answer is: Lavender top tube

The lavender top tube is specifically designed for hematology studies, primarily because it contains the anticoagulant ethylenediaminetetraacetic acid (EDTA). This anticoagulant is effective in preventing blood from clotting, making it ideal for complete blood counts (CBCs) and other hematological assays that require the analysis of whole blood or plasma without the interference of clotting factors. The sterility aspect of the lavender top tube is also important, as some hematology tests may require a clean sample to ensure accurate results and to prevent contamination that could affect the interpretation of white blood cell counts or differential counts. In contrast, other tubes serve different purposes: the red top tube is often used for serum collection and does not contain any additives that prevent clotting, making it unsuitable for hematology testing. The green top tube contains heparin, which is primarily used for chemistry tests. The blue top tube contains citrate, which is generally used for coagulation studies rather than routine hematology. This understanding of the specific uses of blood collection tubes is crucial in veterinary practice to ensure that tests are conducted accurately and efficiently.