PCR-generated artefact from 16S rRNA gene-specific primers.

Artefacts consisting of concatenated oligonucleotide primer sequences were generated during sub-optimally performing polymerase chain reaction amplification of bacterial 16S rRNA genes using a commonly employed primer pair. These artefacts were observed during amplification for terminal restriction fragment length polymorphism analyses of complex microbial communities, and after amplification from DNA from a microbial culture. Similar repetitive motifs were found in gene sequences deposited in GenBank. The artefact can be avoided by using different primers for the amplification reaction.