The Perkin-elmer Corporation

Roche Molecular Systems, Inc.

Deborah E Dodge

Douglas H Smith

Thomas J White

Nicole M Ellis

The invention relates the discovery that the polymorphisms in 16S rRNA genes may be used to identify unknown bacterial isolates at the level of species, subspecies and strain identification. The invention also relates to the discovery that the sequences of individual are required. The invention involves the generation of composite polynucleotide sequence of the 16S rRNA genes of a microorganism of interest. The invention is to provide methods for identifying microorganisms. The methods comprise the steps of generating a composite 16S rRNA region sequence from a microorganism of interest. The composite 16S rRNA region sequence reveals polymorphisms within the 16S ribosomal RNA gene of the microorganism. The composite 16S rRNA region sequence may then be compared with a list of previously obtained composite 16S rRNA region sequences from reference microorganisms so as to determine the species, subspecies, or strain of the microorganism of interest. Another aspect of the invention is to provide computer based methods of identifying a microorganism.

Ribosomal RNA gene polymorphism based microorganism identification

The present invention relates to improved methods of generating polynucleotide sequencing reaction products from cycle sequencing and relates to various instruments and reagents for use in the subject methods. The use of 'step-down' thermal profiles in conjunction with cycle sequencing is described. Step-down thermal profiles are formed by combining several thermal cycle sets such that the annealing temperature of each thermal cycle set is less than the annealing temperature of the preceding thermal cycle set. One embodiment of the invention is a method of generating a plurality of polynucleotide sequencing reaction products in parallel by subjecting a plurality of sequencing solution preparations to a step-down thermal profile, i.e., exposure to repeated thermal cycle sets, each thermal cycle set having an annealing temperature that is lower than the annealing temperature of the annealing phases of the preceding thermal cycle set. Other embodiments of the invention include systems for generating a plurality of polynucleotide sequencing reaction products in parallel. The systems comprise (i) a programmable thermal cycler programmed to perform a step-down thermal profile and (ii) a plurality of polynucleotide sequencing preparations. Additional embodiments of the invention include sets of polynucleotide sequencing reaction preparations that may be used in the methods of the invention. Another aspect of the invention is a device for generating a plurality of polynucleotide sequencing reaction products. The devices of the invention include (i) a plurality of polynucleotide sequencing reaction preparation chambers, each chamber containing a sequencing primer, (ii) a common fluid entry port, and (iii) a fluid dispensing channel, the channel connecting each of the sequencing reaction preparation chambers to the common fluid entry port. At least two of the sequencing primers in the device have Tms different from one another by at least 2.degree. C.

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Albany, CA, United States of America

Deborah E Dodge