Machado-Joseph disease (MJD) is associated with the expansion of a CAG triplet repeat in a novel gene on 14q32.1. We evaluated a non-radioactive detection method for the screen of MJD. This non-radioactive PCR combined with agarose gel electrophoresis provides a comparably sensitive and accurate detectlon method as radioactive PCR wlth polyacrylamide gel electrophoresis. As low as 25 ng of genomic DNA can be speclfically amplified by PCR and the numbers of CAG repeat can be determined by agarose gel electrophoresis. This safe and quick detection method can by used in routine clinical laboratories for screening high-risk population of MJD. Machado-Joseph疾病(MJD)是由於位在染色體14q32.1的MJD基因的CAG三核甘酸不正常延長所造成。在這篇報告中我們評估一個非放射性PCR結合洋菜膠電泳的MJD篩選方式，此法的靈敏度及正確性與放射或PCR結合聚丙烯醯氨電泳相當，只要25ng的染色體DNA，CAG的重複次數即可以被正確的檢驗出來，因此此法可供一般醫療檢驗單位篩選高危險群之用。
