For which test is a PST (Mint Green) tube mainly used?

The PST (Plasma Separator Tube) with a mint green top is primarily used for collecting plasma in a variety of tests, especially in the context of chemistry analyses. It contains lithium heparin as an anticoagulant, which is particularly effective for certain blood tests, reflecting its role in maintaining the integrity of the sample.

Fasting blood sugar tests are one of the primary uses for the PST tube. This type of testing measures the glucose level in the blood after a period without food intake and is crucial for diagnosing conditions like diabetes. The mint green tube allows for efficient processing and separation of plasma from the cellular components, enabling accurate measurement of glucose levels.

In contrast, other types of tests such as kidney function tests, ESR tests, and pregnancy hormone tests typically utilize different tubes based on what substances are being measured or processed. For example, kidney function tests might require specific serum tubes, and ESR tests often use black-top tubes for specialized testing. Therefore, the mint green PST is specifically suited for fasting blood sugar tests, making it the correct answer in this context.