Direct chromosome analysis and FISH were performed on twelve primary gastric carcinomas. Two of them had simple chromosome changes: 48,XX, +8, +20, and 49, XY, +2, +8, +9, and the others had complicated chromosome changes, which includes much more numerical and structural chromosome aberrations. Frequent structural changes in the complicated types involved chromosome 7, 3, 1, 5 and 12 etc. The del 7q was noted in eight cases. The del (3p) and del (1p) were noted in six and five cases, respectively. The results provide some important clues for isolation of the genes related to gastric cancer.

Objective　 This study was aimed at using chromosome painting technique to detect translocation, especially microtranslocations, on chromosomes in comparison with G-banding analysis. Methods　 Chromosome painting technique was applied to analysis of metaphase chromosomes of patients for detecting translocations with biotin-labeled chromosomes X, Y, 14q, 10 specific probes. Results Fluorescence in situ hybridization FISH signals were shown clearly in slides even in specimen stored at room temperature for 10 years and at -80℃. Translocations were located precisely. Conclusion Microtranslocations, which are hard to analyze by G-banding, can be detected exactly using chromosome painting technique with G-band karyotype on metaphase chromosome.