At present, 3 major Direct Enzymatic HbA1c Assay testing methods are available to clinical laboratories, namely;
1. Chromatography based HPLC assay
2. Antibody based immunoassay
3. Enzyme based enzymatic assay
In this blog, we will try to explain the readers how these techniques function.
1. Choromatographic Method:
The chromatographic assay utilizes an HPLC instrument and an ion exchange or affinity column to segregate HbA1c molecules from other hemoglobin molecules respectively. Subsequently, HbA1c content is calculated based on the ratio of its peak areas to the total hemoglobin peak areas.
2. Latex enhanced Immunoassay method:
The latex enhanced immunoassay for HbA1c is established on the interactions involved amidst antigen molecules (HbA1c) and HbA1c specific antibodies coated on latex beads. This cross-link reaction results in changes in the solution turbidity which is proportional to the amount of the antigen in the samples.
3. Enzymatic HbA1c assay method:
Recent developments have yielded a Direct Enzymatic HbA1c AssayTM which uses a single channel test and reports %HbA1c values right away, without the need for a separate THb test or a calculation step.