Final answer:
To prevent contamination of blood specimens with different additives, separate tubes should be used for each specimen. This ensures accurate test results and avoids interference from cross-contamination between additives, which is crucial for reliable blood analysis.
Step-by-step explanation:
To prevent specimens from being contaminated with another tube's additive, the correct approach is to use separate tubes for each specimen. This is essential to ensure that the results of blood tests are accurate and not compromised by cross-contamination between specimens with different additives. For example, blood samples collected into tubes containing additives such as K2EDTA or lithium heparin are used for specific tests and should be handled individually. This avoids any potential interference in the blood analysis process, such as affecting the clotting mechanisms or mingling of anticoagulants that may skew results.
If you mix all the specimens in one tube or use the same tube for all specimens, the additives from each specimen can contaminate others, leading to inaccurate test results. Completely avoiding the use of additives is also not an option, as they are necessary for preserving the blood sample's integrity for specific analyses. For example, to obtain plasma, blood is typically collected into tubes with an anticoagulant and centrifuged. Without the additive, the blood would clot, and plasma could not be separated.
During the process of preparing broth cultures of bacteria, cultures are grown separately and combined just before the lab begins, emphasizing the importance of isolating samples to avoid cross-contamination. Similarly, when a technician is using graduated pipettes, the accurate transfer of sterile and sometimes contaminated liquids is crucial to prevent issues that could arise from mixing different additives or samples.