TABLE 1.

Comparison of standard curves obtained using either water alone or water plus murine DNA^a

Dilution medium and target	Mean Ct at the indicated target copy no.b:						ΔRn from plateauc	Sloped	PCR efficiencye (%)
	106	105	104	103	102	101
Water alone
HIV-1	17.4	21.1	24.4	28.3	31.8	35.2	1.3	−3.57	90
Albumin	17.4	21.6	25.0	28.7	32.3	35.7	1.9	−3.60	89
Water + murine DNA
HIV-1	18.4	21.9	25.9	29.2	32.8	35.6	1.1	−3.51	92
Albumin	18.3	22.0	26.0	29.7	33.5	36.8	1.8	−3.73	85

^aThe amplification parameters for HIV-1 and albumin quantification were obtained with dilutions ranging from 10⁶ to 10¹ copies of the double plasmid standard, and experiments were carried out in either water alone or water containing 1 μg of murine DNA from the BALB/3T3 cell line. 

^bAverage Ct values measured in duplicate for each point of the calibration curve. 

^cAverage values of normalized fluorescence intensity (ΔRn) taken from the plateau of all the amplification curves. 

^dSlopes of the calibration curves. 

^ePercent amplification efficiency, calculated as (10^(−1/slope) − 1) × 100.