There are commercial kits available for microbial RNA amplification such as the MessageAmp TM II-Bacteria RNA Amplification Kit (Life Technologies, Grand Island, NY, USA). There are also other commercially available methods for WCGA. Wang et al. (2011) compared two of these (Bacillus stearothermophilus DNA polymerase (Bst) and REPLI-g; Qiagen, Valencia, CA, USA) with the modified Templiphi kit (Wu et al., 2006a) . The amplification bias for all methods was relatively low (<3-fold). Less bias was observed with REPLI-g and Templiphi for pure culture DNA and with REPLI-g for community DNA while Bst showed the least inhibition by lesser quality DNA.