Which of the following specimens is commonly collected for routine blood tests?

A serum separator tube blood sample is commonly collected for routine blood tests because it is specifically designed to facilitate the separation of serum from blood cells. In clinical practice, this type of specimen is used to obtain a clear serum after the blood has been centrifuged, allowing for various analyses. Routine blood tests such as complete blood counts, metabolic panels, and lipid profiles require serum to provide accurate results.

The other options encompass different types of specimens that are used for various diagnostic purposes but are not typical for routine blood tests. A throat swab is primarily used for microbiological cultures to detect infections like strep throat. A urine sample is utilized for urinalysis or for screening for conditions affecting the renal system or urinary tract. A stool sample is analyzed for gastrointestinal infections, parasites, and digestive health concerns. None of these specimens provide the serum needed for the routine blood tests. Therefore, the choice of a serum separator tube blood sample is essential for the accurate assessment and diagnosis of patients through standard blood analysis.