Comparison of seven RNA extraction methods on stool and shellfish samples prior to hepatitis A virus amplification

When choosing an extraction method, two parameters have to be considered: recovery of the viral material and elimination or inactivation of inhibitory substances. Seven techniques for extracting hepatitis A virus (HAV) from stool and shellfish samples were compared, in order to identify the protocol most suited to both types of sample and with the best extraction yield. The protocols tested were either techniques for the recovery and purification of total RNA, such as RNAzol, PEG-CETAB, GTC-silica and Chelex, or techniques for isolating specifically HAV using a nucleotide probe or a monoclonal antibody. For stool samples, RNAzol, PEG-CETAB, and magnetic beads with antibody allowed detection of the virus in 11/12 and 12/12 of samples. For shellfish samples, three protocols allowed RNA to be extracted in 90% of cases, RNAzol, PEG-CETAB, and GTC-silica. Their rapidity and low cost make RNAzol and GTC-silica the most suitable for routine diagnostic testing. (C) 1999 Elsevier Science B.V. All rights reserved.