HbA1c Assay Technology

HbA1c System Components

Current Status: Scripps Laboratories has demonstrated feasibility of utilizing the technology to develop a low cost, portable HbA1c assay system. Scripps is interested in licensing the technology of the Scripps HbA1c System (patents & know-how) for adaptation into a finished product. 

Assay Principle: The Scripps assay is a boronate affinity method. Both total and glycated hemoglobin are measured on the same disposable assay device.

Meter: Possible to utilize Glucometer type reflectometers

Assay Range: 3 to 13% DCCT harmonized HbA1c

Stability: Assay strip contains no potentially labile components such as enzymes, antibodies or chromogenic markers. Preliminary studies indicate good stability at room temperature and 45°C with desiccation.

Advantages & Features:

1. Small sample size: 2 to 3 µl fingerstick

2. Whole blood capillary sample with no pre-treatment

3. All measurements made on the same area of the matrix, minimizing system error.

4. Short Assay Time: ~5 minutes

5. Low Cost Test Strip

6. Boronate Affinity Method - Will not be affected by the labile fraction of glycated hemoglobin or by the presence of hemoglobin variants in the sample.

Steps for Running an Assay

The steps involved in running an assay are shown below using the proof of concept assay system. Both total and glycated hemoglobin are measured on a single strip using a single whole blood sample, and percent glycated hemoglobin is reported.

Proof-of-Concept Assay Results

Performance data was collected from assays of clinical samples and control materials.

• The clinical sample assay results (ratios) were proportional to the NGSP reference method and could be harmonized with the DCCT.

• The Scripps method met NGSP certification criteria for agreement with reference methods.

• The twenty-day precision study showed CV's of ≤ 4% for HbA1c at 5% and at 11%.

The agreement of the Scripps method to the NGSP Primus reference method is shown below. There was no difference between days in the correlation.

The Bland-Altman plot of the correlation data is shown below. The Scripps method passed the NGSP criteria for agreement to a reference method.
 

Stability Data

The test strips show excellent stability at room temperature and 45°C with desiccation.