[Capillary electrophoretic method for protein determination using bicinchoninic acid-Cu+ colorimetric reaction].
A new rapid, sensitive method for protein determination using capillary electrophoresis and specific colorimetric reaction of bicinchoninic acid (BCA) was established, assisted by microwave incubation. With 60 mmol/L boric acid buffer (pH 9.5) and inclusion additive of beta-cyclodextrin, the complex of BCA-Cu+ and free BCA molecules were efficiently separated. The peak intensity of BCA-Cu+ was higher than those of native proteins about two orders of magnitude at a low wavelength of 200 nm. The linear ranges of this method were from 2 to 200 mg/L for transferrin, and 2 to 100 mg/L for ricin. The limits of detection for transferrin and ricin were 0.33 and 0.37 mg/L, respectively. This method was also successfully applied in the determination of some ricin samples in the First International Proficiency Test on the quantification of ricin.
Beijing Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, Beijing 100850, China.
Qingwei
Q
Meng
Lei
L
Guo
Rui
R
Shen
Jianwei
J
Xie
D003124:Colorimetry / Q000379:methods; D003300:Copper / Q000737:chemistry*; D019075:Electrophoresis, Capillary / Q000379:methods*; D011506:Proteins / Q000032:analysis*; D011804:Quinolines / Q000737:chemistry*
D011506:Proteins; D011804:Quinolines; D003300:Copper; C047117:bicinchoninic acid