Non-covalent labeling of human serum albumin with indocyanine green: a study by capillary electrophoresis with diode laser-induced fluorescence detection.
Indocyanine green (ICG) is a negatively charged, water-soluble, tricarbocyanine dye used primarily for medical imaging. ICG is only weakly fluorescent in the near-infrared region in its free (unbound) state in dilute aqueous solution. However, when non-covalently bound to protein, its fluorescence is greatly enhanced, making it a candidate for diode laser-induced fluorescence (diode-LIF) detection of proteins in capillary electrophoresis (CE). This paper investigates the suitability of ICG as a fluorescent label for the separation and detection of human serum albumin (HSA) by CE with diode-LIF detection. Specifically, we have considered the separation conditions necessary to resolve free ICG from ICG-HSA complexes; the limits of detection for free and HSA-bound ICG; the stability of aqueous ICG and ICG-HSA solutions over time; and the stoichiometry of the ICG-HSA complex.
Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109, USA.
E D
ED
Moody
P J
PJ
Viskari
C L
CL
Colyer
D019075:Electrophoresis, Capillary / Q000379:methods*; D006801:Humans; D007208:Indocyanine Green / Q000737:chemistry*; D007834:Lasers; D012680:Sensitivity and Specificity; D012709:Serum Albumin / Q000737:chemistry*; D012996:Solutions; D013050:Spectrometry, Fluorescence / Q000379:methods
D012709:Serum Albumin; D012996:Solutions; D007208:Indocyanine Green