Robotic chromatography: development and evaluation of automated instrumentation for assay of glycohemoglobin

Abstract

The measurement of glycohemoglobin (GHb) by boronate affinity chromatography is useful in monitoring long-term glucose control in diabetic subjects. The inherent disadvantage of this method is the hands-on time required because the hemoglobin fractions are separated on individual disposable columns. To overcome this disadvantage, we have programmed a Hamilton Microlab 2200 automated pipetting cartesian robot to complete the procedure, from the aspiration of blood from the sample-collection tube to the transfer of the separated hemoglobin fractions to a microtiter plate for absorbance measurement. This automated robotic system can analyze 96 specimens, including patients' samples and control material, in approximately 3 h. The precision (CV) of the method ranged from 1.6% to 3.5% within-run and from 2.7% to 3.5% day-to-day. The results correlated with those obtained with the Accuflex semiautomated robot, which used the identical disposable column, and those obtained with a Primus high-performance liquid chromatograph, which used a regenerated microparticle column. Automation of the GHb procedure allowed improved throughput, reduced labor cost, improved precision, and offered greater laboratory safety.