HIGH-SENSITIVITY LASER-INDUCED FLUORESCENCE DETECTION OF NATIVE PROTEINS IN CAPILLARY ELECTROPHORESIS

A highly sensitive laser-induced (LIF) detection scheme for native, tryptophan- or tyosine-containing proteins in capillary electrophoresis (CE) has been demonstrated. The 275.4 nm line from an argon-ion laser is used to excite native protein fluorescence. A limit of detection (LOD) (S/N = 2) of 1 . 10(-10) M for conalbumin represents a 140-fold improvement over earlier reports. With stacking at injection, the LOD is 3 . 10(-12) M. Linear dynamic ranges of at least 5 and 4 orders of magnitude for, respectively, tryptophan and bovine serum albumin are found. The practical performance and blueprint of an easily constructed, rugged, compact and user-friendly LIF detector for CE are shown.