Rapid quantitative image analysis of hCG by gold immunochromatographic assay and genetic fast FCM algorithm

In this paper, a CCD-based imaging gold immunochromatographic assay system combining genetic fast FCM algorithm is developed for rapid quantitative detection of human chorionic gonadotropin(hCG). The image of gold immunochromatographic strip is taken by CCD sensor, and after using the genetic fast FCM algorithm to precisely extract the test and control lines of strips, the reflective integral optical density(IOD) is selected as the feature based on Lambert-beer law. The ratio (IOD_t/IOD_c) is directly proportional to the concentration of hCG in a sample by which the interference in the test and control lines can be cancelled out each other. We observe a good linearity(correlation of coefficient r = 0.98995) from the construction of standard curve throughout the entire measuring range 0-500mIU/ml, and the detection limit of the proposed method is enough sensitive to detect the hCG in the blood or urine of the pregnancy woman. The precision of the intra-assay expressed as coefficient of variation(CV) is below 12%. The system presented here takes less than 10min to perform from the sample treatment to the data analysis. Relative to scanning reflective optical system, our results suggest that a simple CCD-based imaging system can speed assay development, reduce errors, and improve accuracy.