Abstract: Methods for obtaining nucleic acid from nucleated cells are disclosed, wherein RNA and fragmented genomic DNA can be sequentially obtained from the same starting material are disclosed. In some embodiments, protein can also be obtained from the same starting material as the RNA and DNA are obtained. According to certain methods, whole blood or a blood fraction comprising nucleated cells is combined with a capture surface and at least some of the leukocytes are retained on the surface. The RNA is released from the retained leukocytes, then the capture surface is treated with a suitable nuclease or other DNA fragmenting agent to release DNA fragments. In certain embodiments, either the released RNA, the released DNA, or both the released RNA and the released DNA are employed in one or more molecular biology application.

Abstract: The present invention addresses compositions and methods for cleaving nucleic acids. The invention allows one to reliably detecting point mutations in long and short target regions of nucleic acids in a safe, non-labor intensive, and cost effective manner. The methods and compositions of the present invention allow for the use of various RNases, such as RNase A, RNase I and RNase T2, in the detection of mutations. The present invention also identifies reaction conditions that result in significant improvement in specific mismatch cleavage in the NIRCA.TM. assay.

Abstract: The present invention discloses improved compositions and methods for detecting mutations, including single base changes, in nucleic acid sequences using RNase protection assays. The improvements include concomitant, dramatic reductions in the salt and RNase enzyme concentrations in the RNase digestion reaction mixture which result in greater sensitivity in detecting genetic mutations. Another embodiment of the present invention is kits to be used for the detection of single base mismatches in nucleic acid samples.