Chemiluminescence detection of heme proteins separated by capillary isoelectric focusing

Chemiluminescence detection was combined with capillary isoelectric focusin g to perform protein analysis with high sensitivity. Luminol-H2O2 chemilumi nescence was utilized, and hemeproteins such as cytochrome c, myoglobin and peroxidase were analyzed. The proteins were focused by use of Pharmalyte 3 -10 as ampholytes. Hydroxypropylmethyl cellulose was added to the sample so lution in order to easily reduce protein interactions with the capillary wa ll as well as the electroendoosmotic flow. The focused proteins were transp orted by salt mobilization: to chemiluminescence detection cell equipped wi th an optical fiber. The present method showed significantly high sensitivi ty and wide dynamic range; the detection limit for cytochrome c was 6 . 10( -9) M and the linear dynamic range was greater than two-orders of magnitude (up to 2 . 10(-6) M). (C) 1999 Elsevier Science B.V. All rights reserved.