Automated particle-counting immunoassay for alpha-fetoprotein

Area of Science:

• Biochemistry
• Immunology
• Analytical Chemistry

Background:

• Alpha 1-fetoprotein (AFP) is a crucial biomarker in clinical diagnostics.
• Non-radioimmunoassay methods are sought for safer and more accessible AFP determination.
• Traditional immunoassays can be complex and require specialized handling.

Purpose of the Study:

• To adapt and validate the Particle-based homogeneous non-radioimmunoassay (PACIA) for serum AFP measurement.
• To assess the performance characteristics of the PACIA method for AFP quantification.
• To compare PACIA results with established radioimmunoassay (RIA) techniques.

Main Methods:

• Utilized latex particles coated with F(ab')2 fragments of anti-AFP antibodies.
• Employed an optical cell counter to measure latex particle agglutination.
• Automated the assay with a sampling rate of 50 samples/hour and 26-minute incubation.
• Validated using standard curves (1-50 microgram/L) and analyzing 127 patient samples.

Main Results:

• Achieved analytical recoveries ranging from 93.5% to 98.4%.
• Demonstrated a high correlation coefficient (0.98) with radioimmunoassay.
• Reported maximum intra-assay and inter-assay coefficients of variation (CVs) of 7.4% and 9.6%, respectively.
• Ensured specificity by using F(ab')2 fragments to minimize interference from serum constituents.

Conclusions:

• PACIA is a validated, automated, and homogeneous non-radioimmunoassay for serum AFP determination.
• The method offers high accuracy, precision, and excellent correlation with RIA.
• PACIA presents a viable alternative to radioimmunoassay for routine clinical laboratory use.