[Efficient detection and analysis of linear plasmid in Stremptomyces Men-myco-93-63].

OBJECTIVE: To develop an efficient method to detect and analyze the endogenous plasmid in Stremptomyces Men-myco-93-63. METHODS: According to the property of 'the linear chromosomes and plasmids of Stremptomyces spp.have proteins covalently bound to the 5'ends of the DNA', a novel method was established to detect the type, configuration and size of the Streptomyces spp. plasmids by improving the preparation of agarose embedded block. The method can also show whether the linear plasmids have proteins covalently bound to the DNA from both the positive and negative aspects. RESULTS: The type and configuration of two plasmids were determined efficiently from Stremptomyces roseoflavus Men-myco-93-63 and verified by the two-dimensional electrophoresis. The speculated sizes of these plasmids were 47 kb and 53 kb, respectively. CONCLUSION: Two linear plasmids were detected successfully from Stremptomyces roseoflavus Men-myco-93-63 by a new method.