Quantitative evaluation of lectin‐reactive glycoforms of α1‐acid glycoprotein using lectin affinity capillary electrophoresis with fluorescence detection

α₁‐Acid glycoprotein (AGP) was previously shown to be a marker candidate of disease progression and prognosis of patients with malignancies by analysis of its glycoforms via lectins. Herein, affinity capillary electrophoresis of fluorescein‐labeled AGP using lectins with the aid of laser‐induced fluorescence detection was developed for quantitative evaluation of the fractional ratios of concanavalin A‐reactive or Aleuria aurantia lectin‐reactive AGP. Labeled AGP was applied at the anodic end of a fused‐silica capillary (50 μm id, 360 μm od, 27 cm long) coated with linear polyacryloyl‐β‐alanyl‐β‐alanine, and electrophoresis was carried out for about 10 min in 60 mM 3‐morpholinopropane‐1‐sulfonic acid‐NaOH buffer (pH 7.35). Addition of the lectins to the anode buffer resulted in the separation of lectin‐reactive glycoform peaks from lectin‐non‐reactive glycoform peaks. Quantification of the peak area of each group revealed that the percent of lectin‐reactive AGP is independent of a labeling ratio ranging from 0.4 to 1.5 mol fluorescein/mol AGP, i.e. the standard deviation of 0.5% for an average of 59.9% (n=3). In combination with a facile procedure for micro‐purification of AGP from serum, the present procedure, marking the reactivity of AGP with lectins, should be useful in determining the prognosis for a large number of patients with malignancies.