Final answer:
Flow cytometry, including FACS, diagnoses abnormal blood cells, characterizes cell types, and quantifies specific subsets like CD4 and CD8 T cells, but does not measure metabolites or kidney function.
Step-by-step explanation:
Flow cytometry, often referred to as Fluorescence-Activated Cell Sorting (FACS), is a powerful tool in clinical and research settings for characterizing and quantifying cells in complex mixtures. The technique utilizes fluorescently labeled antibodies to identify and sort cells based on specific cell-membrane proteins. Flow cytometry can diagnose abnormal blood cell profiles or blood cancer subtypes, characterize, count, and sort different blood cell types, and is commonly used in immunology to determine levels of lymphocyte subpopulations such as CD4 and CD8 T cells, which are indicative of a patient's immune status, especially in diseases such as HIV.
However, flow cytometry is not traditionally used to establish blood cholesterol and urea levels, determine kidney filtration rates, or measure serum albumin levels. For these purposes, chemical assays and other diagnostic techniques are employed. Flow cytometry requires the use of isolated cells, and thus is primarily suited for analyzing samples such as peripheral blood or disaggregated tissue cells.