Abstract
A method is described which should permit determination of the order and spacing of genes on all human chromosomes by the analysis of just one set of man-mouse hybrid cells. This method is used to determine the map of 8 loci on human chromosome 1. A comparison of the statistical maps of chromosome 1 and of the X-chromosome with the cytogenetic maps of these chromosomes at metaphase indicates that the statistically derived distances between genes are related to the amount of Giemsa light-band material between the genes.