# Trends in Quantification of HbA1c Using Electrochemical and Point-of-Care Analyzers
## 7 Strategies for Measurement of HbA1c  
Ever since [PERSON] introduced the first measurement method for HbA1c in the 1980s, it has been widely implemented in the clinics for diabetes diagnosis and management. Over the years, additional methods have been introduced for HbA1c quantification. These include chromatography-based methods such as ion exchange chromatography [88], high-performance liquid chromatography (HPLC) [89], and boronate affinity chromatography [90]. Apart from these, other methods such as immunoassay, enzyme-linked immunosorbent assay (ELISA), colorimetric method, liquid chromatography combined with mass spectroscopy, capillary electrophoresis, and fluorometry have been used for HbA1c detection. These techniques require expensive reagents and/or components that limit their utility for screening large population sets. Further, these instruments are not portable, and hence HbA1c measurements are mostly laboratory-based. Advancements in manufacturing technology have resulted in the development of some point-of-care (PoC) analyzers that work on these conventional techniques based on differences in charge (ion-exchange chromatography) and structure (boronate affinity chromatography and immunoassays). These include the commercially available DiaSTAT, DS5, and G7 analyzers that are based on cation-exchange chromatography, and the Vision Analyzer, NycoCard(r), Clover, etc., which are based on boronate affinity chromatography (Table 4). \begin{table}
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**Manufacturer** & **Device Name** & **Method** & **Sample Volume (aL)** & **Detection Range** & **Analysis Time (a)** & **SRA Approachs** & **Ref. ** \\ \cline{2-7} \cline{8-10} \cline{10-10} \cline{6-7} \cline{8-10 \begin{table}
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**Manufacturer** & **Device Name** & **Method** & **Sample Volume (s.l.)** & **Detection Range** & **Analysis Time (s)** & **SRA Approvals** & **Ref.** \\ \hline Jans Care & & & & & & & \\ (Bangloz, Karnatakis, India) & Anaa & Boroutte affinity & 5 & 4-15\%/29-1400 mrad/mad & 180 & CE-IVD & [99] \\ \hline OSANG Healthcare & & & & & & & \\ (Gyropes-06, Republic of Korea) & Cover Alc Plus & Boroutte affinity & 4 & 4-140\%/ & 300 & CE-IVD, FDA & [99] \\  & & & & & & & \\ \hline FTS Diagnostics & & & & & & & \\ (Whitelow, IN, USA) & AlcNow+ & Immunosassay & 5 & 20-120 mrad/mad & 300 & CE-IVD, FDA (CLIA wavel) & [100] \\ \hline Roche Diagnostics & & & & & & & \\ (Rsch-deRinger, Switzerland) & Cobus b 101 & Immunosassay & 2 & 4-10\%/ & 320 & CE-IVD, FDA & [99] \\ \hline Siemens Healthiness & & & & & & & \\ (Ethagen, Germany) & DCA Vantage & Immunosassay & 1 & 2-5-140\%/ & 360 & CE-IVD, FDA (CLIA wavel) & [99] \\  & & & & & & & \\ \hline Wasi SoftEmes Biomedical & & & & & & & \\ Technology Co. (Wasi, China) & & & & & & & \\ \hline \end{tabular}
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Table 4: _Cont._The main advantages of PoC analyzers include ease of use and instantaneous results. However, it must be ensured that these PoC analyzers estimate the quantities of HbA1c in the sample with high accuracy and specificity, and should be cheap and reproducible. A survey analyzing the proficiency of various clinical laboratory techniques employed for HbA1c measurement revealed that nearly 65% depend on an immuno-turbidometric assay for HbA1c measurement, 32% are based on ion-exchange chromatography, while >2% are based on boronate affinity chromatography [102]. Another study compared the efficacy of eight HbA1c PoC analyzers, namely, Quo-Test (Quotient Diagnostics, Surrey, UK), In2 it (Bio-Rad, Hercules, CA, USA), NycoCard, (Abbott), Afinion (Abbott), AlCNow (Bayer, Berkeley, CA, USA), DCA Vanteg (Siemens), Clover (Infopia, Koln, Germany), and InnovaStar (DiaSys, Holzheim, Germany). The results suggested that DCA Vanteg and Afinion compared with the criteria in the National Glycochemoglobin Standardization Program (NGSP), with a total imprecision (CV) below 3% [103]. Another comparative study evaluated the performances of the PoC analyzers Afinion and DCA Vanteg with the HPLC technique.