Table 2.

Effects of 16 PCR facilitators on amplification capacity of rTth DNA polymerase in the presence of feces and meat

Facilitator and facilitator concncPCR resultsa with the following at the indicated concn (% [vol/vol])b:
FecesMeat
20420.40.220420.40.2
Acetamide
 0−, −−, −−, −+, ±+, +−, −−, −±, −+, ±+, ±
 1−, −−, −−, −+, −+, ±−, −−, −−, −+, ±+, +
 2.5−, −−, −−, −+, −+, ±−, −−, −−, −+, −+, ±
 4−, −−, −−, −±, −+, −−, −−, −−, −±, −±, −
Betaine
  0−, −−, −−, −+, −+, +−, −−, −−, −±, +±, +
  5.9−, −−, −−, −+, −+, +−, −±, −+, −±, ++, +
  8.8−, −−, −−, −+, ±+, +−, −−, ±±, ±+, ++, +
 11.7−, −−, −−, −+, ++, +−, −−, −+, −+, ++, +
BSA
 0−, −−, −−, −−, ++, +−, −−, −±, −+, ++, +
 0.2−, −+, −±, ±−, ++, ++, ++, ++, ++, ++, +
 0.4−, −+, ±+, ++, ++, ++, ++, ++, ++, ++, +
 0.6−, −−, ±−, ++, ++, ++, ++, ++, ++, ++, +
Dextran 40
 0−, −−, −−, −+, ++, +−, −−, −±, −+, ++, +
 1−, −−, −−, −+, ++, +−, −+, −±, ++, ++, +
 2.5−, −−, −+, −+, ++, +−, −−, −−, −+, ++, +
 4−, −−, −−, −+, ++, +−, −−, −+, ++, ++, +
Dextran 500
 0−, −−, −−, ++, ++, +−, −−, −+, ±+, ++, +
 1−, −−, −−, −+, ++, +−, −−, −±, −+, ++, +
 2.5−, −−, −−, −+, ++, +−, −−, −±, −+, ++, +
 4−, −−, −−, −+, ++, +−, −−, −−, −±, ++, +
Dimethyl sulfoxide
 0−, −−, −−, −+, ++, +−, −−, −±, −±, ++, +
 2.5−, −−, −−, −+, ++, +−, −−, −−, −±, ++, +
 5−, −−, −−, −+, ++, +−, −−, −−, −−, ±+, +
 7.5−, −−, −−, −+, −+, −−, −−, −−, −−, −±, −
Formamide
 0−, −−, −−, −+, ++, +−, −−, −±, ±±, ++, +
 0.25−, −−, −−, −+, −+, +−, −±, −±, −±, ++, +
 0.5−, −−, −−, −+, −+, +−, −−, −±, −+, −+, +
 1−, −−, −−, −+, −+, −−, −−, −±, −±, −+, −
Glycerol
 0−, −−, −−, −+, ++, +−, −−, −−, −+, ++, +
 5−, −−, −−, −+, ++, +−, −−, ±−, ±+, ++, +
 7.5−, −−, −−, −+, ++, +−, −−, ±+, ±+, ++, +
 10−, −−, −−, −+, ++, +−, −−, ±−, ++, ++, +
gp32
 0−, −−, −+, ++, ++, +−, −−, −−, −+, ++, +
 0.01−, −+, ++, ++, ++, +−, −+, ++, ++, ++, +
Nonidet P-40
 0−, −−, −−, −+, ++, +−, −−, −−, ±+, ++, +
 0.1−, −−, −−, −+, ++, +−, −−, −−, −+, ++, +
 0.25−, −−, −−, −+, ++, +−, −−, −−, −+, ++, +
 0.5−, −−, −−, ±+, ++, +−, −−, −−, −+, ++, +
Polyethylene glycol 400
 0−, −−, −−, −+, ++, +−, −−, −−, −+, ++, +
 1−, −−, −−, ±+, ++, +−, −−, −−, −−, +±, +
 2−, −−, −−, ±+, ++, +−, −−, −−, −−, +±, +
 4−, −−, −−, ±+, ++, +−, −−, −−, −−, ±−, +
Polyethylene glycol 4000
 0−, −−, −−, −+, ++, +−, −−, −−, −+, ++, +
 1−, −−, −−, ±+, ++, +−, −−, −−, −+, ++, +
 2.5−, −−, −−, ++, ++, +−, −−, −−, −−, ++, +
 4−, −−, −−, ±+, ++, +−, −−, −−, −±, ±±, +
Proteinase inhibitord
 0−, −−, −−, −+, ++, +−, −−, −±, −+, ++, +
 0.25×−, −−, −+, ±+, ++, +−, −−, −−, −+, ++, +
 0.5×−, −−, −+, ±+, ++, +−, −−, −±, −+, −+, +
 1×−, −+, ±+, ±+, ++, +−, −−, −−, −±, −+, +
TMAC
 0−, −−, −−, −+, ±+, +−, −−, −−, −±, ++, +
 2.8 × 10−4−, −−, −−, −+, ±+, ±−, −−, −−, −+, ++, +
 5.5 × 10−4−, −−, −−, −+, ±+, +−, −−, −−, −±, ++, +
 1.1 × 10−3−, −−, −−, −+, ±+, +−, −−, −−, −±, ++, +
Tween 20
 0−, −−, −−, −+, ++, +−, −−, −−, −±, ±+, +
 0.1−, −−, −−, −+, ++, +−, −−, −±, −±, ±+, +
 0.25−, −−, −−, −+, ++, +−, −−, −−, −+, ±+, +
 0.5−, −−, −−, −+, ++, +−, −−, −−, −±, ++, +
Tween 80
 0−, −−, −−, −+, ++, +−, −−, −−, −+, ++, +
 0.1−, −−, −−, −+, ++, +−, −−, −±, −+, ±+, +
 0.25−, −−, −−, ±+, ++, +−, −−, −±, −+, ++, +
 0.5−, −−, −−, ++, ++, +−, −−, −±, −+, ++, +
  • a Results are of two independent PCR results; +, PCR product of high yield; ±, PCR product of low yield; −, no PCR product. The results were recorded in the order in which the PCRs were done.

  • b Percentage (vol/vol) of homogenates of feces and meat in PCR mixture for rTth containing 1 ng of L. monocytogenes DNA.

  • c Percentage (wt/vol) of 16 amplification facilitators in the reaction mixtures. The PCR sensitivity in the presence of the concentrations of these facilitators was the same as that with a solution of pure water with DNA.

  • d One tablet of Proteinase Inhibitor Complete Mini cocktail (EDTA-free; Roche Molecular Biochemicals) was dissolved in 2 ml of deionized water. This concentration was five times greater than that recommended by the supplier.