All-Food-Seq (AFS): a quantifiable screen for species in biological samples by deep DNA sequencing

BMC Genomics

Table 3 Mapping results for the reference sausage KalD

Species	Target value [%]	Proportion [%]		Difference abs. [%]		Difference rel. [%]
Species	Target value [%]	AFS-quant	AFS-spec	AFS-quant	AFS-spec	AFS-quant	AFS-spec
Cattle	35	36.05 ± 0.04	41.16 ± 0.02	1.05 ± 0.04	6.16 ± 0.02	3 ± 0.11	17.6 ± 0.03
Horse	1	1.27 ± 0.01	1.45 ± 0.01	0.28 ± 0.01	0.45 ± 0.01	27.67 ± 0.67	45 ± 1
Pig	9	7.22 ± 0.05	7.59 ± 0.09	1.79 ± 0.05	1.41 ± 0.09	19.85 ± 0.48	15.67 ± 1
Sheep	55	54.76 ± 0.09	49.71 ± 0.08	0.24 ± 0.09	5.29 ± 0.08	0.44 ± 0.17	9.62 ± 0.15
Waterbuffalo	0	0.64 ± 0.03	0.07 ± 0	0.64 ± 0.03	0.07 ± 0	n.a.	n.a.
Total	100			4 ± 0.1	13.38 ± 0.04

Quantitative species analysis obtained by Illumina sequencing of DNA from the “KalD” reference sausage [37]. The AFS-quant and AFS-spec approaches (see text for details) were compared. Each dataset tested contained 1 mio of paired-end sequence reads, randomly selected from a larger dataset. Three different sub-datasets (1 mio reads each) were analyzed and mean values plus standard deviations are displayed. “Difference abs.” shows the difference between the proportion of reads as determined by AFS (“proportion”) relative to the expected amounts existing in the sample (“target value”). “Difference rel.” is calculated by dividing “Difference abs.” by the expected proportion value.

ISSN: 1471-2164