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 progra m uses DNA marker data and selects the semilogarithmic linear range (s l-range), i.e., the linear portion of the semilogarithmic curve (mobil ity vs. log of DNA fragment length). Over this range a linear interpol ation is derived for calculating the size of a DNA fragment whose mobi lity falls in the sl-range. The program also derives a hyperbolic inte rpolation formula that covers the entire range for determining the siz e of a DNA fragment whose mobility is beyond the semilogarithmic linea r range. The method described in this paper is sensitive, accurate and reliable. This program can also be used to compnte protein or polypep tide size from sodium dodecyl sulfate polyacrylamide gel electrophores is data. The DOSTM version of the DNASIZE proram is freely available f rom Netserver at EMBL or from BioTechNet((R)) by EMail.