Abstract: The present invention provides a method for quantitatively analyzing microbial genes, species, or strains in a sample that contains at least two species or strains of microorganisms. The method involves using an isothermal DNA polymerase to randomly and representatively amplify genomic DNA of the microorganisms in the sample, hybridizing the resultant polynucleotide amplification product to a polynucleotide microarray that can differentiate different genes, species, or strains of microorganisms of interest, and measuring hybridization signals on the microarray to quantify the genes, species, or strains of interest.

Abstract: The present invention provides a method for quantitatively analyzing microbial genes, species, or strains in a sample that contains at least two species or strains of microorganisms. The method involves using an isothermal DNA polymerase to randomly and representatively amplify genomic DNA of the microorganisms in the sample, hybridizing the resultant polynucleotide amplification product to a polynucleotide microarray that can differentiate different genes, species, or strains of microorganisms of interest, and measuring hybridization signals on the microarray to quantify the genes, species, or strains of interest.

Abstract: The present invention is a method for determining the presence or absence of a microorganism in a sample. The method involves providing a nucleic acid microarray having one or more probes that represent at least a substantial portion of the whole genomic DNA or RNA of the microorganism, hybridizing a labeled DNA or RNA preparation derived from the sample to the microarray, washing the microarray, and observing the presence or absence of a hybridization signal at the position where the one or more probes are located to determine the presence or absence of the microorganism in the sample.