P. Holownia et al., ADAPTATION OF LATEX-ENHANCED ASSAY FOR PERCENT GLYCOHEMOGLOBIN TO A DADE DIMENSION(R) ANALYZER, Clinical chemistry, 43(1), 1997, pp. 76-84
At present no method for glycohemoglobin (%HbA(1c)) is automated on a
main-line analyzer to allow joint measurement with other indicators of
diabetic control such as glucose and cholesterol. We describe an adap
tation of a latex-enhanced competitive immunoassay for quantifying %Hb
A(1c) to the Dade International Dimension(R) analyzer. After a manual
hemolysis step, HbA(1c) and total hemoglobin (Hb) are determined separ
ately. The concentration of glycated beta-subunit is obtained from the
immunoassay, whereas Hb is assessed colorimetrically from a derivatiz
ed form. Both reactions were fully optimized for accuracy, precision,
and specificity on the Dimension; stabilities of reagents and calibrat
ion were established; and potential interferences were assessed. The a
nalyzer gave reliable results over the required clinical range of 1-15
% HbA(1c). Within-run and total assay variation were within 5% of the
target CV limits, as determined by ANOVA with three representative sam
ple pools across 20 days. Close agreement with an established HPLC pro
cedure and a commercially available enzyme immunoassay was observed fo
r 140 samples from clinically defined patient groups. Additional sampl
es from patients with hemoglobinopathies (n = 20) demonstrated a more
complex relationship between methods. We conclude that adaptation of t
he method for use with the Dimension analyzer is a valid method for qu
antifying %HbA(1c).