Development of a chemiluminescent immunoassay based on magnetic solid phase for quantification of homocysteine in...

Homocysteine (HCY) is a sulfur-containing amino acid that is an independent or important risk factor for the occurrence of many chronic diseases and is one of the most important indicators for determining health risks. However, existing HCY detection methods do not meet the requirements of clinical diagnosis. Therefore, there is an urgent need to establish new detection methods to meet the needs of clinical detection.

In this study, we used the principle of competitive method to establish a new method for the determination of HCY in human serum using a chemiluminescent enzyme immunoassay in conjunction with a chemiluminescent assay instrument that uses magnetic microparticles as the solid phase of the immunoreaction. The established method achieved satisfactory results in terms of minimum detection limit, specificity, accuracy, and clinical application. The limit of detection was 0.03 ng/mL. The intra-assay coefficient of variation (CV) was 1.94-5.05%, the inter-assay CV was 2.29-6.88%, and the recovery rate was 88.60-93.27%. Cross-reactivity with L-cysteine ranged from 0.0100 to 0.0200 μmol/L, and cross-reactivity with glutathione ranged from 0.0100 to 0.200 μmol/L, all of which were less than the limit of detection (LoD) of this method. The linear factor R of this method was greater than 0.99.

In summary, the developed method showed a good correlation with the product from Abbott. A total of 996 clinical patients with cardiovascular diseases were evaluated using the method developed in this study.