Development of a Colloidal Gold- based lateral flow immunoassay for the rapid detection of glycosylated hemoglobin (HbA1c) in whole blood

Globally, diabetes mellitus (DM) is one of the major health problems. DM prevalence is increasing rapidly and causing disability and death. So, early and accurate diagnosis of DM is very important to prevent the further complications. In this study, a lateral flow immunoassay (LFA) was developed to detect glycosylated hemoglobin (HbA1c). Colloidal gold particle labeled monoclonal anti-glycosylated hemoglobin (clone 16) was used as the detector reagent. Monoclonal antibodies for anti-hemoglobin (clone 6) and anti-mouse IgG were immobilized in test and control lines, respectively, of a nitrocellulose membrane, acting as the capture reagents. The LFA was used to detect HbA1c in 500 sera from clinically proven DM patients. The intensity and number of the test lines on the LFA strips differentiate normal, pre-diabetic (under control) and diabetic (elevated levels of HbA1c). The results from our LFA were validated and compared with Alere Afinion AS 100 HbA1c analyzer and Bio-Rad variant II- HPLC obtained good data. Moreover, the test strip was stable at 4-30°C temperature for up to 6 months. The HbA1c LFA was highly selective for HbA1c and showed no cross reactivity against HbA0, glycated HbA0, HbA2. Thus, the developed colloidal gold based LFA proved to be simple, rapid, inexpensive, point-of-care method with good specificity and sensitivity.