Immunoassay detection in a perfluorocarbon emulsion oxygen therapeutic

The effect of a perfluorocarbon emulsion oxygen therapeutic (PEOT) on detecting theophylline was explored using a commercial EMIT® (enzyme multiplied immunoassay technique) immunoassay. The EMIT technique is based on a colorimetric reaction, the product of which can be measured spectrophotometrically. The intent was to determine whether the presence of PEOT interferes with this detection. We found that the immunoassay yields excellent quantitative data in the therapeutic range (10–20 ppm theophylline) in 2–10% PEOT, but as the amount of PEOT in the sample increases, the accuracy of the detection method decreases.