Table 1. Comparison of DNA extraction methods.

Extraction Method	Manual Time (hr)	Automated Time (hr)	A260/A280 mean ± s.d.	A260/A230 mean ± s.d.	Amplification
QIAmp® PowerFecal®	1.5–2	N/A	1.84 ± 0.02	1.68 ± 0.23	40/40
Maxwell RSC PureFood GMA Authentication	0.5	0.6	2.04 ± 0.03	1.86 ± 0.15	39/40

Time of extraction method determined from start of fecal processing to DNA elution and separated into manual and automated components. Mean 260/280 nm and 260/230 nm absorbance ratios (± s.d.) for each extraction method. With respect to more stringent filtering associated with DADA2, successful amplification was defined as minimal coverage of 100 reads per sample. n = 40 per extraction method.