利用分子選殖法，將salmonella trphimurium PT782 之染色體DNA以限制酶BamH I切割，黏結於同樣限制酶切割之YEp 13 中，送入Escherichia coli MC1061，從E. coli轉形株中，共篩選到7株轉形株含BamH I DNA片段，初步發現不會與E. coli之 total DNA進行雜交反應。這些插入DNA片段大小分別為 5.0、2.0、1.7、2.5、2.5、2.5及3.0 kb。進一步將這些DNA片段與本研究室收集之沙門氏菌及非沙門氏菌，包括與沙門氏菌血緣相近之腸內菌進行菌落雜交反應，確認這些DNA片段之特異性。由結果發現，轉形株2-6，8-4之插入DNA對所有沙門氏菌具有足夠的特異性，可作為沙門氏菌檢測之用。 With YEp 13 as cloning vector, Escherichia coli MC 1061 as host cell and the BamHΙ digested chromosome DNA from Salmonella typhimurium PT782 as DNA source, we have cloned several DNA fragments specific for the detection of salmonellae. From the E. coli transformants, seven clones containing the BamHΙ fragments were preliminary found not to hybridize with the total DNA of E. coli. Molecular size of these fragments were 5.0, 2.0, 1.7, 2.5, 2.5, 2,5, 3.0kb respectively. Further confirmation of the specificity for these DNA fragments were performed by colony hybridization with 132 salmonella isolate and 55 non-salmonella isolates including the salmonellae closely related enterobacteria. Results were found that two BamHΙ fragments obtained from transformants 2-6 and 8-4 were specific enough for the detection of all salmonellae.