To identify quantitative chromosomal variations or markers corresponding to the neoplastic conversion of cell lines, with the ultimate hope of being able to characterize cells converted by viruses on the basis of these markers. To achieve these objectives, several goals were set: 1. To develop a banding techique that would produce consistent and specific bands that can be used for computer analysis. 2. To develop a computer program that can not only measure the banded chromosomes, but also would analyze the banding patterns. 3. To apply those banding techniques and their computer analysis to Chinese hamster cell cultures. 4. To develop primary Chinese hamster monolayer cultures for quantitative chromosome measurements before and after treatment with SV-40 virus.