Abstract: A method for determining the presence and/or amount of a first polynucleic acid in a sample comprising subjecting the sample to nucleic acid amplification in which product is detectable by the presence of a signal generated by polynucleic acid formation from the first polynucleotide characterised in that the nucleic acid amplification reaction is conducted, in the same reaction vessel, with a predetermined amount of a second polynucleic acid which is subjected to nucleic acid amplification, the product of which is detectable by the presence of the same signal generated by polynucleic acid formation from the second polynucleotide as that generated by polynucleic acid formation from the first polynucleotide and wherein the product of the second polynucleic acid is produced with different reaction kinetics from the product of the first polynucleic acid such that the second polynucleic acid acts as an internal control for the method.