OBJECTIVES: We attempted to define optimal conditions for amplification of low copy number HIV-1 RNA sequences in plasma samples, applying improved conditions for nucleic acid extraction and amplification. METHODS: Several methodologic parameters were evaluated, including methods of RNA extraction, volumes of plasma samples, proportion of extracted RNA used as a template for amplification, and reverse transcriptase-DNA polymerase enzyme combination employed in cDNA synthesis and polymerase chain reaction amplification. RESULTS: With this improved assay, we were able to obtain sufficient amounts of amplified material for direct sequencing in 97% of all plasma samples in our study, including 88% of samples with viral loads <80 copies/mL, 78% of samples with viral loads <50 copies/mL, and even 2 (67%) of 3 samples with <20 copies/mL. CONCLUSIONS: This procedure could be useful for testing resistance mutations in patients undergoing highly active antiretroviral therapy, in which the viral load is commonly <400 copies/mL, and even if it is <20 RNA copies/mL.
OBJECTIVES: We attempted to define optimal conditions for amplification of low copy number HIV-1 RNA sequences in plasma samples, applying improved conditions for nucleic acid extraction and amplification. METHODS: Several methodologic parameters were evaluated, including methods of RNA extraction, volumes of plasma samples, proportion of extracted RNA used as a template for amplification, and reverse transcriptase-DNA polymerase enzyme combination employed in cDNA synthesis and polymerase chain reaction amplification. RESULTS: With this improved assay, we were able to obtain sufficient amounts of amplified material for direct sequencing in 97% of all plasma samples in our study, including 88% of samples with viral loads <80 copies/mL, 78% of samples with viral loads <50 copies/mL, and even 2 (67%) of 3 samples with <20 copies/mL. CONCLUSIONS: This procedure could be useful for testing resistance mutations in patients undergoing highly active antiretroviral therapy, in which the viral load is commonly <400 copies/mL, and even if it is <20 RNA copies/mL.
Authors: Shivani Gupta; Tracy Taylor; Aileen Patterson; Binhua Liang; Jared Bullard; Paul Sandstrom; Gary Van Domselaar; Hezhao Ji Journal: Biomed Res Int Date: 2017-04-03 Impact factor: 3.411
Authors: Yuka Nadai; Lindsay M Eyzaguirre; Niel T Constantine; Anne M Sill; Farley Cleghorn; William A Blattner; Jean K Carr Journal: PLoS One Date: 2008-01-09 Impact factor: 3.240