Method of detecting mutations in DNA and RNA
First Claim
1. A method of detecting a mutation of a specific nucleotide base in a target nucleic acid chain by providing a linear probe complementary to a part of the nucleic acid chain extending in one direction from the specific base,(a) hybridizing the probe to the target to form a nucleic acid hybrid, whereby one end of the probe becomes hybridized to the nucleic acid chain substantially adjacent the specific base,(b) admixing with the hybrid a nucleotide derivative, under conditions appropriate for probe extension, so as to cause the nucleotide derivative to join on to the end of the probe only if the specific base in the target is, or is not, the mutation to be detected, a probe carrying said nucleotide derivative being resistant to digestion under particular conditions, wherein one of the probe and the nucleotide derivative is labelled,(c) subjecting the hybrid to digestion by an exonuclease enzyme under the said conditions whereby the double-stranded portion thereof is progressively digested starting at the said end of the probe unless the end has had said nucleotide derivative joined to it,(d) removing portions of the probe which are no longer hybridized to the nucleic acid chain,(e) and using the presence or absence of the probe remaining after digestion to detect a mutation of the specific nucleotide base in the target.
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Accused Products
Abstract
A method of detecting a mutation of a specific nucleotide base in a target nucleic acid chain comprises: (a) hybridizing a labelled probe to the target to form a hybrid in which one end of the probe is positioned adjacent the specific base; (b) adding a nucleotide derivative, e.g. a thionucleotide, under conditions to cause it to join to the end of the probe if it is complementary to the specific base; (c) digesting the hybrid using an exonuclease enzyme under conditions such that the nucleotide derivative protects the probe from digestion; and observing the presence or absence of label attached to the target. The method can be used to detect mutations even when these are not present at restriction enzyme cleavage sites, and does not require the preliminary steps of restriction digestion, gel electrophoresis and DNA (or RNA) blotting.
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Citations
14 Claims
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1. A method of detecting a mutation of a specific nucleotide base in a target nucleic acid chain by providing a linear probe complementary to a part of the nucleic acid chain extending in one direction from the specific base,
(a) hybridizing the probe to the target to form a nucleic acid hybrid, whereby one end of the probe becomes hybridized to the nucleic acid chain substantially adjacent the specific base, (b) admixing with the hybrid a nucleotide derivative, under conditions appropriate for probe extension, so as to cause the nucleotide derivative to join on to the end of the probe only if the specific base in the target is, or is not, the mutation to be detected, a probe carrying said nucleotide derivative being resistant to digestion under particular conditions, wherein one of the probe and the nucleotide derivative is labelled, (c) subjecting the hybrid to digestion by an exonuclease enzyme under the said conditions whereby the double-stranded portion thereof is progressively digested starting at the said end of the probe unless the end has had said nucleotide derivative joined to it, (d) removing portions of the probe which are no longer hybridized to the nucleic acid chain, (e) and using the presence or absence of the probe remaining after digestion to detect a mutation of the specific nucleotide base in the target.
Specification