Automated Glycated Hemoglobin Assay Now Certified by US Glycohemoglobin Standardization Program

An assay for the measurement of glycated hemoglobin (HbA1c) designed for use on a new-generation automated chemistry analyzer was recently certified by the [US] National Glycohemoglobin Standardization Program (NGSP).

HbA1c is a derivative of hemoglobin that is formed nonenzymically by reaction at the N terminus of the protein molecule with glucose. In the normal adult human such derivatives constitute a few percent of the total erythrocyte hemoglobin, the most abundant being hemoglobin A1c, which increases several fold in concentration in diabetes mellitus, and is assayed to monitor control of diabetes. Once a hemoglobin molecule is glycated, it remains that way. A buildup of glycated hemoglobin within the red cell, therefore, reflects the average level of glucose to which the cell has been exposed during its life-cycle. Measuring glycated hemoglobin assesses the effectiveness of therapy by monitoring long-term serum glucose regulation. The HbA1c level is proportional to average blood glucose concentration over the previous four weeks to three months.


In the United States, HbA1c testing laboratories are certified by the National Glycohemoglobin Standardization Program (NGSP) to standardize them against the results of the 1993 Diabetes Control and Complications Trial (DCCT). This landmark study showed that the risk for development and progression of the chronic complications of diabetes was closely related to the degree of glycemic control, as measured by HbA1c. The DCCT also provided a large body of data relating HbA1c values to mean blood glucose.

Carolina Liquid Chemistries Corporation (Winston-Salem, NC, USA) recently announced today that its new Hemoglobin A1c test (HbA1c-direct), designed for use on the CLC720 chemistry analyzer had been certified by the NGSP.

“There are other HbA1c tests on the market,” said Patricia Shugart, chief operating officer at Carolina Liquid Chemistries Corporation, “but our HbA1c-direct is special in two ways. First, it’s a direct test, meaning there is no manual sample pretreatment. Second, it is categorized as moderately complex, which avoids the extra cost of a high complexity lab.”

The speed and ease of HbA1c-direct is made possible by the enhanced capabilities of the CLC720 chemistry analyzer, which, unlike most analyzers in its class, automates the lysing step that would otherwise have to be performed manually.

“Our test correlates to the NGSP certified tests used in large-scale diabetes studies,” said Patricia Shugart. “Physicians can now relate their HbA1c-direct results to these studies, providing more relevance.”

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Carolina Liquid Chemistries Corporation