Collection method Smooth surface (microscope slide) Absorbent surface (white cotton)
DNA conc. pg/μL Number of drop-out alleles Number of drop-in alleles DNA conc. pg/μL Number of drop-out alleles Number of drop-in alleles
1:1000 Applimed SA swab 8.93 2.7 (2) 9 (3) - 29.3 (33) 6.3 (0)
16.93 2 (2) 3.3 (1) 3.33 25.7 (27) 15.7 (8)
22.69 3.7 (2) 7 (1) - 31 (34) 10.3 (1)
Dryswab™ 60.21 2 (2) 1.7 (0) 4.84 19 (19) 8.7 (3)
38.91 2 (2) 0 (0) - 21.7 (25) 9.7 (1)
55.57 2.7 (2) 2.7 (0) 3.89 27.7 (28) 8.3 (1)
1:5000 Applimed SA swab 5.58 17.7 (19) 5.3 (0) - 33 (34) 1 (0)
5.48 16.7 (17) 2 (0) - 32.3 (34) 1.3 (0)
4.71 19.7 (24) 3.3 (0) 3.45 33 (34) 0.3 (0)
Dryswab™ 7.58 5.3 (2) 5 (1) 6.81 22 (34) 10.3 (9)
9.84 5.3 (4) 5 (2) - 31 (34) 1.3 (1)
9.35 9 (7) 4.7 (0) - 28.3 (34) 0.7 (0)
Table 1: Evaluation of the quality of DNA profiles obtained from samples of diluted blood deposited on smooth and absorbent surfaces, and collected by two different cotton swabs. An average number of drop-out and drop-in alleles are given for the three profiles obtained per extract. The numbers in brackets represent the number of drop-out and drop-in alleles still present in the consensus profile. Note that extracts obtained from pure blood samples were not amplified.