Table 2. The non-human samples and negative extraction controls were amplified 84 times in Linköping and 28 times in Stockholm/Uppsala, producing 8 amplicons in Linköping and 28 in Stockholm/Uppsala.

Samples	Linköping			Stockholm/Uppsala
	No. PCRs	Contaminated	Freq C	No. PCRs	Contaminated	Freq C
Non-human	43	4	0.75	16	16	0.156
Extraction blank	41	4	1	12	12	0.125
PCR blank	39	6	0.7	12	6	0.17

The frequencies of the contaminating C-allele are given.