Mutation detection by denaturing DNA chromatography using fluorescently labeled polymerase chain reaction products.
A specialized form of ion-pair reversed-phase high-performance liquid chromatography is gaining widespread application in mutation detection for single nucleotide polymorphisms (SNP). The technique relies on temperature-modulated heteroduplex analysis (TMHA) by chromatographic separation of partially denatured DNA heteroduplexes from homoduplexes. Here, we demonstrate that fluorescent labeling is compatible with mutation analysis by this form of DNA chromatography and offers advantages over the use of unlabeled DNA fragments. Uniform labeling of wild-type and mutant alleles for TMHA yields peak patterns identical to unlabeled fragments. However, fluorescent labels increase retention times but do not influence resolution of heteroduplexes from homoduplexes. They increase sensitivity and decrease the amount of DNA required for analysis; e.g., in the case presented here, one allele can be detected in the presence of a 500-fold excess of another allele. Furthermore, allele-specific wild-type probes, fluorescently labeled on one strand only, make it possible to selectively monitor specific homoduplexes and wild-type/mutant heteroduplexes. This, in combination with an internal homoduplex standard, greatly reduces the complexity of fluorescence chromatograms compared with chromatograms recorded in the UV. These simplified chromatograms, in which only the internal homoduplex standard and the labeled heteroduplex are detected in the presence of a mutation, greatly facilitate the detection and identification of mutant alleles.
Transgenomic, Inc., San Jose, California 95131, USA.
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Hecker
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Taylor
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Gjerde
D001483:Base Sequence; D004247:DNA / Q000235:genetics* / Q000302:isolation & purification; D004252:DNA Mutational Analysis / Q000379:methods; D005456:Fluorescent Dyes; D005819:Genetic Markers; D006801:Humans; D008297:Male; D021141:Nucleic Acid Amplification Techniques; D009691:Nucleic Acid Denaturation; D009692:Nucleic Acid Heteroduplexes / Q000235:genetics / Q000302:isolation & purification; D016133:Polymerase Chain Reaction / Q000379:methods; D018807:Polymorphism, Single-Stranded Conformational; D014998:Y Chromosome / Q000235:genetics*
D005456:Fluorescent Dyes; D005819:Genetic Markers; D009692:Nucleic Acid Heteroduplexes; D004247:DNA