Handling and detection of 0.8 amol of a near-infrared cyanine dye by capillary electrophoresis with laser-induced fluorescence detection.
We are interested in the detection of DNA adducts and other trace analytes by labeling them with a fluorescent tag followed by use of capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) for high resolution and sensitivity. Towards this goal, here we report the following: (1) synthesis and handling properties of a near-IR, carboxyl-substituted heptamethine cyanine dye; (2) modification of an existing ball lens LIF detector to provide near-LIF detection with excitation at 785 nm for CE; and (3) corresponding handling and detection of as little as 0.8 amol of the dye by enrich-injection of 4.7 microl of 1 x 10(-13) mol/l dye in methanol from an 8-microl volume into a corresponding CE-LIF system. The electrolyte for the separation was methanol-40 mmol/l aqueous sodium borate (98:2, v/v). This finding encourages further exploration of the dye by functionalization of its carboxyl group for chemical labeling purposes.
Yang
Changming
C
Department of Pharmaceutical Sciences at the Bouve College of Health Sciences, Northeastern University, Boston, MA 02115, USA.
Shimelis
Olga
O
Zhou
Xiaojuan
X
Li
Guoding
G
Bayle
Christophe
C
Nertz
Michel
M
Lee
Hyeran
H
Strekowski
Lucjan
L
Patonay
Gabor
G
Couderc
Francois
F
Giese
Roger W
RW
D002232:Carbocyanines / Q000032:analysis*; D004396:Coloring Agents / Q000032:analysis*; D019075:Electrophoresis, Capillary / Q000379:methods*; D007834:Lasers; D009682:Magnetic Resonance Spectroscopy; D013050:Spectrometry, Fluorescence / Q000379:methods*; D019265:Spectroscopy, Near-Infrared
D002232:Carbocyanines; D004396:Coloring Agents