Which method is the most sensitive for quantitation of AFP?

The quantitation of alpha-fetoprotein (AFP) is crucial in various clinical scenarios, particularly in the diagnosis and monitoring of certain cancers and liver conditions. The enzyme immunoassay (EIA) is recognized for its high sensitivity and specificity in measuring low concentrations of biomolecules in serum samples.

Enzyme immunoassays use enzymes linked to antibodies, which react with substrates to produce a measurable signal, usually through color change or fluorescence. This signal can be amplified, making EIA particularly useful when detecting small amounts of AFP in patient samples. The sensitivity of EIA allows for the detection of AFP levels that might be too low for other methods to reliably determine, thereby facilitating accurate diagnosis and monitoring.

In contrast, other methods such as double immunodiffusion may not provide adequate sensitivity for detecting low levels of AFP, as this technique relies on the diffusion of antibodies and antigens in a gel medium, which can limit quantification in low-concentration scenarios. Electrophoresis, while useful for separating proteins based on size and charge, does not specifically quantify analytes like AFP with the same precision and sensitivity as EIA. Particle agglutination is a rapid method for detecting antibodies or antigens but generally lacks the sensitivity needed for