Table 2.

Mean relative abundance of amplification of unexpected bacteria which results from two primer sets targeting the V3-V4 and V4 region of the 16S rRNA gene which were used for amplification of mock community cells extracted with the RBBC (MC) and mock community DNA amplified at both 20 and 28 cycles.

	Primer comparison
	V3–V4	SEM	V4	SEM	P-value
BLAST_DS_20	0.16	0.01	0.17	0.01	NS
BLAST_DS_28	0.96	0.03	0.63	0.03	<0.05
BLAST_MC_20	0.57	0.03	0.56	0.08	NS
BLAST_MC_28	1.47	0.06	1.19	0.04	<0.05

P-values were calculated using a Mann–Whitney U-test to compare background amplification from each treatment group (n = 5) which results from the primer set utilized.