Abstract:

OBJECTIVE: To develop a method for human 550-850 band high-resolution chromosome preparation with advantages such as high mitotic division index and good dispersion rate. METHODS：High-resolution chromosomes were prepared from 10 periphearal blood samples. Doses of 5-fluorouridine，uridine， thymidine，ethidium bromide and demecolcine were constant among 15 experimental designs through arranging 5 factors and 3 standards. 5 factors were adding time of 5-fluorouridine and uridine，action time of thymidine， ethidium bromide and demecolcine. 3 standards referred to addition of 5-fluorouridine and uridine at 64，72 and 80 h，action time of thymidine for 16，17 and 18 h， of ethidium bromide for 3，4 and 5 h，of demecolcine for 10，15 and 20 min，and hypo-osmotic time for 30，40 and 50 min. Each specimen underwent all 15 kinds of treatment designs at the same time. And high-resolution chromosome division index and good dispersion rate were compared among 15 designs. RESULTS：Great significant differences on high-resolution chromosome division index were found from the action time of 5-fluorouridine，uridine and demecolcine (P＜0.01). The highest division index of high-resolution chromosome was obtained when cells had been cultured for 72 h before adding 5-fluorouridine and uridine and havested 15 min after adding demecolcine. The best dispersion high-resolution chromosomes could be made when cells had been diluted for 40 min at 37 ℃. CONCLUSION：The method of human high-resolution chromosome preparation from the first experimental design，with advantages such as high cell division index and good dispersion rate，showed great value to be extended to G-banding preparation.

Key words:  high-resolution chromosome, G-banding, demecolcine, division index