In cancer diagnosis, which test is preferred for determining high specificity against the substance of interest?

The enzyme-linked immunosorbent assay (ELISA) is preferred for determining high specificity against the substance of interest in cancer diagnosis because of its ability to quantitatively detect and measure specific proteins, antibodies, or antigens in a sample. This assay uses enzyme-conjugated antibodies that produce a detectable signal upon reaction, allowing for precise quantification. ELISA can be designed to target specific cancer markers, leading to increased specificity for the substance being measured.

In comparison, serum protein electrophoresis is primarily used to separate proteins based on size and charge, which provides information about overall protein composition but lacks the specificity and sensitivity that ELISA offers for individual cancer biomarkers.

Western blotting is effective for protein identification and confirmation, as it involves separation via gel electrophoresis, followed by transfer to a membrane and probing with antibodies. While it can demonstrate the presence of specific proteins, it is often more complex and less amenable to high-throughput optimization than ELISA.

Immunohistochemistry is valuable for locating specific proteins within tissues, providing spatial context in the tumor microenvironment, but does not offer the same quantitative measures as ELISA. It often requires tissue samples rather than liquid biopsies like blood, which limits its application in some diagnostic