METHYLATION DETECTION METHOD

摘要

A method of determining whether a given single nucleotide is methylated or not methylated characterised by the steps of (a) contacting the single nucleotide with one or more hybridisation probe types each of which in its unused form comprises (1) a first oligonucleotide to which is attached one or more first detectable elements in an essentially undetectable state and which further comprises (i) double- and single-stranded regions and (ii) a region resistant to exonucleolytic degradation attached to the end of the double-stranded region adjacent the single-stranded region and (2) a second single-stranded oligonucleotide to which is attached one or more second detectable elements also in an essentially undetectable state and which is adapted to be at least in part the nucleotide sequence compliment of the single-stranded region of the first oligonucleotide; (b) for the relevant probe type causing (i) the single nucleotide to bind to the region resistant to exonucleolytic degradation and the single-stranded region and (ii) the second oligonucleotide to bind to the single nucleotide and the single-stranded nucleotide region to create a substantially double-stranded used probe; either (c1) treating the used probe with a methylation-dependent restriction endonuclease under conditions whereby the used probe is cleaved adjacent the region resistant to exonucleolytic degradation into two double-stranded oligonucleotide products if the single nucleotide is methylated or (c2) treating the used probe with a methylation-sensitive restriction endonuclease under conditions whereby the used probe is cleaved adjacent the region resistant to exonucleolytic degradation into two double-stranded oligonucleotide products if the single nucleotide is not methylated; and thereafter either (d1) treating the product of step (c1) with an exonuclease or a polymerase exhibiting exonuclease activity to liberate either only first or both first and second detectable elements in a detectable state if the single nucleotide is methylated, or only the second detectable elements if not or (d2) treating the product of step (c2) with an exonuclease or a polymerase exhibiting exonuclease activity to liberate either only first or both first and second detectable elements in a detectable state if the single nucleotide is not methylated, or only the second detectable element if the single nucleotide is methylated.

主权项

1. A method of determining whether a given single nucleotide is methylated or not methylated, the method comprising: (a) contacting the single nucleotide with one or more hybridisation probe types each of which in its unused form comprises (1) a first oligonucleotide to which is attached one or more first detectable elements in an essentially undetectable state and which further comprises (i) double- and single-stranded regions and (ii) a region resistant to exonucleolytic degradation attached to the end of the double-stranded region adjacent the single-stranded region and (2) a second single-stranded oligonucleotide to which is attached one or more second detectable elements also in an essentially undetectable state and which is adapted to be at least in part the nucleotide sequence compliment of the single-stranded region of the first oligonucleotide; (b) for the relevant probe type causing (i) the single nucleotide to bind to the region resistant to exonucleolytic degradation and the single-stranded region and (ii) the second oligonucleotide to bind to the single nucleotide and the single-stranded nucleotide region to create a substantially double-stranded used probe; either (c1) treating the used probe with a methylation-dependent restriction endonuclease under conditions whereby the used probe is cleaved adjacent the region resistant to exonucleolytic degradation into two double-stranded oligonucleotide products if the single nucleotide is methylated or (c2) treating the used probe with a methylation-sensitive restriction endonuclease under conditions whereby the used probe is cleaved adjacent the region resistant to exonucleolytic degradation into two double-stranded oligonucleotide products if the single nucleotide is not methylated; and thereafter either (d1) treating the product of step (c1) with an exonuclease or a polymerase exhibiting exonuclease activity to liberate either only first or both first and second detectable elements in a detectable state if the single nucleotide is methylated, or only the second detectable elements if the single nucleotide is not methylated or (d2) treating the product of step (c2) with an exonuclease or a polymerase exhibiting exonuclease activity to liberate either only first or both first and second detectable elements in a detectable state if the single nucleotide is not methylated, or only the second detectable element if the single nucleotide is methylated.