TABLE 2.

Effects of different concentrations of buffy coat, plasma, platelets, and erythrocytes on PCR^a

Concn (%)	PCR resultsb
	Buffy coat	Platelet concentrate	Plasma	Erythrocytes
20	−, −	−, −	−, −	−, −
2	−, −	−, −	−, −	−, −
0.2	−, −	−, −	−, −	−, −
0.02	−, −	±, −	±, −	−, −
0.002	+, +	+, +	+, +	±, +

^aPercentage (vol/vol) of different blood fractions in the PCR mixtures containing 1 ng of L. monocytogenes DNA and AmpliTaq Gold. 

^bResults of two independent PCRs. Symbols: +, band of high intensity; ±, band of low intensity; −, no band.