Improved estimation of DNA fragment length from gel electrophoresis data using a graphical method

A computer program has been developed for computing DNA fragment size from its electrophoretic mobility using a graphical method. The program uses DNA marker data and selects the semilogarithmic linear range (sl-range), i.e., the linear portion of the semilogarithmic curve (mobility vs. log of DNA fragment length). Over this range a linear interpolation is derived for calculating the size of a DNA fragment whose mobility falls in the sl-range. The program also derives a hyperbolic interpolation formula that covers the entire range for determining the size of a DNA fragment whose mobility is beyond the semilogarithmic linear range. The method described in this paper is sensitive, accurate and reliable. This program can also be used to compute protein or polypeptide size from sodium dodecyl sulfate polyacrylamide gel electrophoresis data. The DOS version of the DNASIZE program is freely available from Netserver at EMBL or from BioTechNet by email