Generation of HIV-1 and Internal Control Transcripts as Standards for an In-House Quantitative Competitive RT-PCR Assay to Determine HIV-1 Viral Load

Table 2

RNA concentration of the HIV-1 and IC transcripts determined by spectrophotometry at 260 nm.

Transcript batch	Dilution factor	OD at 260 nm (AU)	A260/280 ratio	RNA concentration (μg/mL)
T-IC-1^a	20	0.550	1.556	440.0
T-IC-1^b	20	0.793	1.614	634.4
T-IC-2^a	35	0.118	1.586	165.2
T-IC-2^b	35	0.817	1.664	1143.8
T-HIV1-1^a	35	1.163	1.687	1628.2
T-HIV1-1^b	35	0.225	1.665	315.0
T-HIV1-2^a	35	0.471	1.543	659.4
T-HIV1-2^b	35	1.183	1.700	1656.2

AU: absorbance units.
OD: optical density.
A260/280 ratio: the ratio of absorbance at 260 and 280 nm.
^aTranscript treated with 2 u of RNase-free DNase per 1 μg of DNA used in the in vitro transcription.
^bTranscript treated with 4 u of RNase free DNase-per 1 μg of DNA used in the in vitro transcription.