Abstract: The invention provides a method and kit for preventing inhibition of a thermal cycling reaction by protein coagulation in a sample.

Abstract: We describe a quantitative PCR (qPCR) instrument for combined qPCR and melt curve (dissociation and/or association curve) analysis. The instrument has at least one optical channel; a fluorescence excitation source; a fluorescence detector; an electronic analog signal amplifier having an input coupled to an output of the fluorescence detector; and an analog-to-digital converter (ADC) having analog input coupled to an output of the analog signal amplifier. The instrument further comprises a quantified automatic gain control (AGC) loop coupled between the signal output of the fluorescence detector and the analog input of the ADC. The AGC loop is configured to apply a determined, numerical gain value to a fluorescence signal for the analog input of the ADC. The instrument also includes a system to scale a digital output of the ADC responsive to the numerical gain value and to provide a digital fluorescence level signal from the scaled digital output.

Abstract: A method and an oligonucleotide probe are described for determining the presence or absence of mutant alleles in a genomic locus. The probe binds to different alleles of a target sequence with different melting temperatures (Tm). The method determines the Tm of the probe when it is hybridized to the target sequence to establish whether a variant nucleic acid such as a mutant allele is present or absent in the target sequence. There may be variants in a target sequence that are not of interest, for example phenotypically silent mutations. To ensure that these variants do not influence the Tm of the probe, the probe contains universal base sites where such variants of no interest occur.