Abstract
GELYSIS (GEL analYSIS) is a Pascal implementation of an algorithm that takes data on the distances migrated by DNA fragments in a one-dimension electrophoretic gel and calculates the sizes of the fragments based on the known sizes of marker fragments. A key step in the overall algorithm is a cubic-spline best-fit of marker calibration data. An option of the program is the generation of graphic representations of the gel and of the calibration spline that are convenient for primary data storage or for publication. Provision is made for specifying different band intensities in the graphic output of the gel.