Direct and quantitative detection of HIV-1 RNA in human plasma with a branched DNA signal amplification assay.
OBJECTIVE
To determine the relative effect of sample matrix on the quantitation of HIV RNA in plasma.


METHODS
Two HIV-positive specimens were diluted into five and 10 different HIV-negative plasma samples, respectively. Branched DNA signal amplification technology and reverse-transcriptase polymerase chain reaction were used to measure the viral load.


RESULTS
In one sample the viral load by polymerase chain reaction ranged from undetectable to 1.9 x 10(5) copies/ml, and the branched DNA results ranged from 2.6 x 10(4) to 4.2 x 10(4) HIV RNA equivalent/ml. In the other sample the corresponding figures were 6.3 x 10(4) to 5.5 x 10(5) copies/ml and 5.7 x 10(4) to 7.5 x 10(4) HIV RNA equivalents/ml.


CONCLUSIONS
In contrast to reverse-transcriptase polymerase chain reaction the branched DNA signal amplification assay does not require a separate extraction step or enzymatic amplification of the target. Therefore this measurement is less affected by the sample matrix and the signal generated is directly proportional to the viral load.
Urdea
M S
MS
Nucleic Acid Systems, Chiron Corporation, Emeryville, California 94608.
Wilber
J C
JC
Yeghiazarian
T
T
Todd
J A
JA
Kern
D G
DG
Fong
S J
SJ
Besemer
D
D
Hoo
B
B
Sheridan
P J
PJ
Kokka
R
R
D004279:DNA, Viral / Q000235:genetics; D005784:Gene Amplification; D015658:HIV Infections / Q000097:blood / Q000382:microbiology*; D015497:HIV-1 / Q000235:genetics* / Q000302:isolation & purification*; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods / Q000706:statistics & numerical data; D012367:RNA, Viral / Q000097:blood* / Q000235:genetics*; D012680:Sensitivity and Specificity; D014766:Viremia / Q000097:blood / Q000382:microbiology; D014773:Virology / Q000379:methods* / Q000706:statistics & numerical data
D004279:DNA, Viral; D012367:RNA, Viral