Handling and detection of 25 amol of near-infrared dye deoxynucleotide conjugates by capillary electrophoresis with laser-induced fluorescence detection.
Near-infrared dyes are attractive as labeling reagents to enhance sensitivity in trace analysis largely because background fluorescence is low in this spectral region. Here we demonstrate, towards a goal of detecting DNA adducts in small biological samples, that some near-infrared (IR) dye-labeled deoxynucleotides can be separated and detected with high sensitivity by capillary electrophoresis (CE)-laser-induced fluorescence detection (LIF) in a realistic way (handling detection limit of 25 amol) for near-IR dye-labeled deoxynucleotides. This detection limit is achieved by polarity-switching injection of 2.0 microl from a volume of 5.0 microl, in which the compounds are 5 x 10(-12) mol/l in 50% aqueous methanol. Although the adenine and cytosine-containing conjugates co-migrated, the other three (guanine, N2-ethylguanine and thymine) were resolved.
Li
Guodong
G
Department of Pharmaceutical Sciences, Bouve College of Health Sciences, Barnett Institute, Northeastern University, Boston, MA 02115, USA.
Gao
Jianxin
J
Zhou
Xiaojuan
X
Shimelis
Olga
O
Giese
Roger W
RW
D004396:Coloring Agents / Q000737:chemistry*; D018736:DNA Adducts / Q000032:analysis*; D019075:Electrophoresis, Capillary / Q000379:methods*; D007834:Lasers; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods*
D004396:Coloring Agents; D018736:DNA Adducts