Variation between homologues and sister chromatids in individual karyotypes.

Chromatid absolute length and density profile from electron micrograph images of human group A chromosomes were studied in an attempt to identify significant individual karyotypic variation. The variation within sister chromatids can be utilized as an internal standard to establish a limit of variability for the purpose of demonstrating differences between homologues. Homologous chromosomes were found to differ with respect to absolute length and density profile.