TABLE 7.

Effect of Na ions on the amplification capacities of nine thermostable DNA polymerases

DNA polymerase	PCR resultsa with NaCl concn (mM)b of:
	10	20	40	60	80	100	150
AmpliTaq Gold	++	++	−−	−−	−−	−−	−−
Expand High Fidelity	++	++	++	++	−−	−−	−−
HotTub	++	++	++	++	++	−−	−−
Pwo	++	++	++	−−	−−	−−	−−
rTth	++	++	++	++	++	±−	−−
Taq	++	++	++	++	−−	−−	−−
Tfl	++	++	++	++	−−	−−	−−
Tli	++	++	++	++	−−	−−	−−
Ultma	++	++	−−	−−	−−	−−	−−

^aTwo independent PCR results. Symbols: +, band of good intensity; ±, band of low intensity; −, no band. 

^bConcentrations of NaCl in the PCR mixtures containing 1 ng of L. monocytogenes DNA.