In Vitro Glycation
Canterbury Scientific Ltd can produce the abnormal level (Level 2) HbA1c control by a process of controlled in vitro glycation of non-diabetic blood. This means there is not a reliance on sourcing blood from diabetic subjects with high HbA1c levels, and it also means that levels of up to over 20% can be produced if required. It also avoids the potential ethical issues relating to obtaining blood from a patient with a clinical condition.
In vitro glycation essentially glycates the same amino acid residues as are glycated in the native glycated hemoglobin. But the ratio of α:β chain glycation is higher in the in vitro product. This means that there is an increase in the proportion of glycation at sites other than the HbA1c site. This makes no difference in procedures such as ion exchange HPLC, or immuno assay where the analytical method specifically measures the HbA1c directly (i.e. measures the glycation of the β N-terminal valine). However it means that with glycation specific type assays such as the boronate affinity method the calculated HbA1c figure (with the increased proportion of glycation at sites other than the HbA1c site) will be higher than when the same glycated sample is measured on the 2 other method types. The normal level control is unaffected since it has been glycated in vivo.