Table 3.

Purity of extracts in routine casework using Microsep 30 K and Amicon Ultra 30 K

Sample type	Inhibition following Microsep 30 K purification (1 May 2011 to 31 August 2011)	Inhibition following Amicon Ultra 30 K purification (1 October 2011 to 29 February 2012)
Rape case samples	41% (n = 1,432)	16% (n = 2,094)
Hairs	31% (n = 94)	26% (n = 130)
Touch stains on mini-tape	43% (n = 1,439)	26% (n = 2,641)
Organically extracted samples	52% (n = 21)	11% (n = 18)

Crime scene DNA extracts are defined as PCR-inhibitory if they generate a shift of the Quantifiler Human IPC Cq compared to the normal value for pure reactions.