Abstract: The present invention provides an efficient and economical method for reducing carryover contamination in an amplification procedure. The method of the present invention enables background caused by contaminant amplification product to be reduced or eliminated through the incorporation of at least one modification into the amplification product. The modified amplification product is readily distinguishable from the target sequence in a test sample. Prior to amplifying the target in a new test sample, the sample may be treated to selectively eliminate the contaminant amplification product so that it cannot be amplified in the new sample.