There are three new methods with superior performance that need to be considered. HbA1c by (i) Capillary electrophoresis (Sebia Capillarys) (ii) by enzymatic digestion (Abbott Chemistry) and (iii) by ion exchange (BioRad D100). All three methods have excellent imprecision CV(SD) < 1.5%. The reference method is enzymatic digestion and mass spectrometry (only for purists!), so the Abbott method is closest by incorporating the enzymatic digestion but using colorimetric reaction rather than mass spec to estimate the N terminal glycation.
However, quality shouldn't be judged by imprecision alone as accuracy and specificity are also issues. In terms of accuracy, all methods are fairly accurate around the diagnostic decision point of 6.5% (48 mmol/mol). However, they do tend to drift in accuracy when you get to much lower values (eg biases of up to 0.5% @ 5.0% ie in the healthy reference interval) or higher values (biases if 1.0% @8.0% or higher ie in the poorly controlled diabetic ranges).
Specificity is also an issue as mentioned by others. Genetic haemoglobin variants including the persistence of fetal haemoglobin can affect the HbA1c value given, so I agree that having a chromatogram, by ion exchange or capillary electrophoresis is preferrable so that abnormal haemoglobins that affect the reliability of HbA1c measurement, can be registered. In general terms, all the new methods have been designed to be robust so that haemoglobin variants generally affect only 1% of all HbA1c analyses - which is very good (unless you happen to belong to the 1% who are mislead).
I would be happy to use any of the three new methods mentioned above, however I would prefer the new BioRad D100 ion exchange method for it's overall imprecision, accuracy and specificity.
Hi Adedeji, unfortunately there are still debates about what is the best way to measure HbA1c.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3819436/
I used to do it using FT-IR spectroscopy and having fully glycated HB as a 100 % standard.
i experianced in HPLC,and so - is the first option and then chromatography
The high-performance liquid chromatography (HPLC) method is the gold standards for HbA1c determination because it will allow identification of abnormal hemoglobins that may reduce the half life of hemoglobin and thus cause erroneous interpretations of the results. This technique measures HbA1c rather than total glycosylated hemoglobin, which is preferred. In some systems HbF overlaps HbA1 that can be a problem.
Immunoanalysis would be the second choice because the antibodies are directed against HbA1c and not total, as in column chromatography.
Bio Rad Variant t II Turbo instrument which work on HPLC principle which is more accurate and reliable
There are three new methods with superior performance that need to be considered. HbA1c by (i) Capillary electrophoresis (Sebia Capillarys) (ii) by enzymatic digestion (Abbott Chemistry) and (iii) by ion exchange (BioRad D100). All three methods have excellent imprecision CV(SD) < 1.5%. The reference method is enzymatic digestion and mass spectrometry (only for purists!), so the Abbott method is closest by incorporating the enzymatic digestion but using colorimetric reaction rather than mass spec to estimate the N terminal glycation.
However, quality shouldn't be judged by imprecision alone as accuracy and specificity are also issues. In terms of accuracy, all methods are fairly accurate around the diagnostic decision point of 6.5% (48 mmol/mol). However, they do tend to drift in accuracy when you get to much lower values (eg biases of up to 0.5% @ 5.0% ie in the healthy reference interval) or higher values (biases if 1.0% @8.0% or higher ie in the poorly controlled diabetic ranges).
Specificity is also an issue as mentioned by others. Genetic haemoglobin variants including the persistence of fetal haemoglobin can affect the HbA1c value given, so I agree that having a chromatogram, by ion exchange or capillary electrophoresis is preferrable so that abnormal haemoglobins that affect the reliability of HbA1c measurement, can be registered. In general terms, all the new methods have been designed to be robust so that haemoglobin variants generally affect only 1% of all HbA1c analyses - which is very good (unless you happen to belong to the 1% who are mislead).
I would be happy to use any of the three new methods mentioned above, however I would prefer the new BioRad D100 ion exchange method for it's overall imprecision, accuracy and specificity.
How is Biorad D10 performance in HbA1c measurement? What is the cost of the instrument and reagent per test?
The best performing method is capillary electrophoresis & second is ion exchange. Beside methods, economics of test run is matter. If you have high volume cost per test will be low in both methods.
Does the HPLC (BioRad D100) method measure the glycated hemoglobin teramer (i.e.a2b2) or just the glycated beta chain?
How does HPLC method is used for glycated hemoglobin detection.how accurately it can measure in case of animal blood.
Hi sir,
I am confused with the question. You want to ask the quantify methods for Glycation estimation or more related to characterization. I am also working on glycation of proteins and in characterization, I follow UV, fluorescence based approaches and MALDI analysis.
I recommend this company Exocell (http://exocell.com/reagents.html) They have excellent antibodies and ELISA kits.
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