Patent ID: 7541144

Claim:
A method of sample analysis comprising: a) heating a sample comprising a plurality of miRNAs to at least 80° C. under conditions including at least 40% DMSO; b) contacting said sample with RNA ligase in the presence of a labeled substrate under conditions sufficient to result in coupling of the labeled substrate to the miRNAs in the sample to provide labeled miRNAs, the conditions including a DMSO concentration in the range from about 20% to about 30%, wherein the labeled substrate comprises an observable label moiety and a nucleotide moiety, the nucleotide moiety having a 5′ phosphate and a 3′ terminus, the observable label moiety directly attached to the 3′ terminus, wherein the observable label moiety is selected from a chromogenic moiety or a fluorophore; c) contacting said labeled miRNAs to an array of probes under conditions suitable for said labeled miRNA to hybridize to said probes; and d) interrogating said array to provide quantitative data on binding of said labeled miRNAs to said array.