Immunoassay for quantifying squamous cell carcinoma antigen in serum

Area of Science:

• Biochemistry
• Immunology
• Clinical Chemistry

Background:

• Squamous cell carcinoma antigen (SCCa) quantification in serum offers clinical utility but faced reagent unavailability in the US.
• The lack of SCCa reagents necessitated the development of a new assay for its measurement.

Purpose of the Study:

• To develop and validate a microtiter plate-based ELISA for serum SCCa quantification.
• To address the clinical need for SCCa measurement following reagent discontinuation.

Main Methods:

• A microtiter plate-based ELISA was developed using monoclonal anti-SCCa antibodies for coating and detection.
• The assay incorporated a biotinylated antibody, streptavidin/horseradish peroxidase conjugate, and TMB substrate.
• A novel blocking reagent was evaluated to mitigate human antimouse antibody (HAMA) interference.

Main Results:

• The developed ELISA demonstrated linearity up to 40 microg/L SCCa with a detection limit of 0.3 microg/L.
• High precision was observed with low intra-assay and inter-assay coefficients of variation.
• The assay showed excellent correlation with an established automated method and effectively eliminated HAMA interference.

Conclusions:

• The SCCa ELISA exhibits acceptable performance characteristics for serum SCCa quantification.
• The assay is effective in overcoming HAMA interference, restoring a valuable biomarker measurement.