Construction of an antibody microarray based on direct labeling strategy for microalbuminuria measurement / 中华肾脏病杂志

ABSTRACT

Objective To build an antibody microarray based on direct labeling strategy for microalbnrninuria measurement, and evaluate it's technical potentiality for clinical application. Methods Urine samples of diabetic patients were collected. Antibody microarrays were constructed by preparation of array support, array fabrication, then protein assay and data analysis were performed. Procedure conditions for each step especially the labeling of samples were optimized. The set-ups were evaluated in terms of sensitivity, specificity and reproducibility. Urinary albumin excretion in the samples was detected by fabricated protein array, which was compared to that detected with immunoturbidimetry. Results The signal intensity was best when protein quality ratio of pure albumin or urine sample against NHS-biotin was 21. A calibration curve with a correlation coefficient of 0.9995 was established. The lower limit of detection was 0.0617 mg/L. Interehip and intrachip variation studies conducted on patient urine demonstrated CVs as 6.78%-9.22% and 3.35%-7.59%, respectively. Compared with the immunoturbidimetry, the antibody microarray was able to detect the extremely lower grade albumin in urine samples. The correlation coefficient of the results obtained by the two methods was 0.9199 (P <0.01). Conclusion An antibody microarray based on direct labeling strategy for microalbuminuria measurement is successfully established, which is comparable to immunoturbidimctry in its accuracy and will have great potential for clinical use with its high throughput, sensitivity, specifity and reproducibility.