Isolation of HIV-1 RNA from plasma: evaluation of seven different methods for extraction (part two)

Some new commercial methods for the extraction of viral RNA have been intro duced recently. In addition to the study published previously (Verhofstede, C., Reniers, S., Van Wanzeele, F., Plum J., 1996. AIDS 8, 1421-1427), seve n different methods (four newly developed and three reference methods) for extraction of HIV-1 RNA from plasma have been evaluated. The RNA preparatio n method that gave the best results (acceptable reproducibility, highest se nsitivity: reasonable price, fast and easy to perform), was the QIAamp Vira l RNA kit from QIAgen. The High Pure Viral RNA Kit (Boehringer Mannheim) as well as the non-commercialised extraction kits were also very sensitive. T he non-commercial tests seem less suitable for routine use and for the proc essing of large number of samples. Two methods, RNA Insta-Pure LS (Eurogent ec) and PANext RNA extraction kit 1 (NTL, PANsystems GmbH) are not adapted for HIV plasma extraction. The single step methods using glass fibre or sil ica column are rapid (from 60 to 75 min depending on the number of wash ste ps) and although the price is high they are cheaper than the Boom extractio n methods: High Pure Viral RNA Kit (Boehringer Mannheim) ($3.3/sample), QIA amp Viral RNA Kit (Qiagen) ($3.6/sample), Boom extraction ($5/sample). The Qiagen kit is the only kit that combines sensitivity with reproducibility, it is commercialised, rapid and affordable in price and can be automated. F or most of the methods evaluated the inter-test variability was acceptable (mean variation coefficient between duplicate extractions varied between 26 .4 and 48.6%). (C) 1998 Elsevier Science B.V. All rights reserved.