Evaluation of an immunoluminometric assay for the AFP determination

We evaluated a two-site immunoluminometric assay (AFP LIA-mat byk) for the alpha-fetoprotein (AFP) determination. The assay, involving two monoclonal antibodies which recognize two different epitopes of the AFP, is rapid (approximately 4 h), with a wide working range (0-600 IU/ml) and a good sensitivity of detection. It presents a good reproducibility (CV less than 10% for the total working range). The regression equation for the AFP LIA-mat (Y) and the AFP bridge Serono (X) was Y = 1.175X-2.27 (n = 95, r = 0.996). It didn't present hook effect and, when we assessed the linearity by assaying a high concentration of AFP, it gave a linear response down to 3.5 IU/ml.