When the DNA samples prepared from inoculated produce en-
richments were tested with the Eppendorf mastercycler ep
gradient S thermal cycler 44-min amplification run, the sensitivity
of detection remained in the 1.6 0.3 103
Shigella cells per ml
range (data not shown), but the PCR efficiency (yield) appeared
slightly lower, especially for virB (Fig. 5), as expected (Fig. 3).