TY - JOUR
T1 - A comparison of electrophoretic resolution for snapshot and finish-line imaging
AU - Sutherland, John C.
AU - Fisk, David J.
AU - Monteleone, Denise C.
AU - Trunk, John G.
N1 - Funding Information:
We thank Drs. Betsy Sutherland, John Dunn, Mark Quasada, and Peter Takacs for helpful discussions and assistance with the construction and evaluation of the laser scanner, Dr. F. William Studier for his support of this project, and Kiley Reynolds and David Soren-son for their comments on the manuscript. This research was supported by the Of®ce of Health and Environmental Research, U.S. Department of Energy, under Contract DE-AC02±76CH00016.
PY - 1996/8/1
Y1 - 1996/8/1
N2 - Finish-line imaging, in which DNA or other macromolecules are detected after electrophoresis for a constant distance, usually improves resolution compared to snapshot imaging, in which molecules are electrophoresed for a constant time in an apparatus of comparable dimensions. Resolving power, which is an objective measure of the ability of different separatory methods to detect closely spaced molecular species, can be used to compare directly the performance of systems employing both snapshot and finish-line imaging [E. A. Ribeiro and J. C. Sutherland, Anal. Biochem. 210, 378-388 (1993)]. Experimentally determined values of resolving power are influenced both by the method of imaging (snapshot vs finish-line) and by instrument-specific factors that affect resolution. Previous comparisons of the resolving power obtained with finish-line and snapshot imaging involved data sets acquired by different instruments with different instrumental resolutions. To reduce the influence of instrumental effects, we constructed a scanning laser fluorometer that can measure both snapshot and finish-line images of fluorochrome-labeled DNA. Snapshot and finish-line images of a DNA sample containing HaeII restriction fragments of the DNA from bacteriophage T7, which range in length from 474 to 6514 base pairs, were obtained under otherwise identical electrophoretic conditions. Snapshot and finish-line imaging give similar resolving powers for DNA molecules up to about 1.5 kbp long. For both imaging modes, maximum resolving power was achieved for DNA molecules between 2 and 3 kbp in length. For larger DNA molecules, finish- line imaging provided higher resolving power. The ratio of the resolving power of finishline images to that of snapshot images increased monotonically as a function of DNA length. For the longest restriction fragments studied (6514 bp), the resolving power for finish.line images exceeded that of snapshot images by about 50%.
AB - Finish-line imaging, in which DNA or other macromolecules are detected after electrophoresis for a constant distance, usually improves resolution compared to snapshot imaging, in which molecules are electrophoresed for a constant time in an apparatus of comparable dimensions. Resolving power, which is an objective measure of the ability of different separatory methods to detect closely spaced molecular species, can be used to compare directly the performance of systems employing both snapshot and finish-line imaging [E. A. Ribeiro and J. C. Sutherland, Anal. Biochem. 210, 378-388 (1993)]. Experimentally determined values of resolving power are influenced both by the method of imaging (snapshot vs finish-line) and by instrument-specific factors that affect resolution. Previous comparisons of the resolving power obtained with finish-line and snapshot imaging involved data sets acquired by different instruments with different instrumental resolutions. To reduce the influence of instrumental effects, we constructed a scanning laser fluorometer that can measure both snapshot and finish-line images of fluorochrome-labeled DNA. Snapshot and finish-line images of a DNA sample containing HaeII restriction fragments of the DNA from bacteriophage T7, which range in length from 474 to 6514 base pairs, were obtained under otherwise identical electrophoretic conditions. Snapshot and finish-line imaging give similar resolving powers for DNA molecules up to about 1.5 kbp long. For both imaging modes, maximum resolving power was achieved for DNA molecules between 2 and 3 kbp in length. For larger DNA molecules, finish- line imaging provided higher resolving power. The ratio of the resolving power of finishline images to that of snapshot images increased monotonically as a function of DNA length. For the longest restriction fragments studied (6514 bp), the resolving power for finish.line images exceeded that of snapshot images by about 50%.
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U2 - 10.1006/abio.1996.0308
DO - 10.1006/abio.1996.0308
M3 - Article
C2 - 8811892
AN - SCOPUS:0030219860
SN - 0003-2697
VL - 239
SP - 136
EP - 144
JO - Analytical Biochemistry
JF - Analytical Biochemistry
IS - 2
ER -