Efficient amplification with NASBA of hepatitis B virus, herpes simplex virus and methicillin resistant Staphylococcus aureus DNA.

A new mechanism is described for DNA amplification using nucleic acid sequence-based amplification (NASBA) including a restriction enzyme digestion and P1 primer binding directly upstream of the digestion. For hepatitis B virus (HBV), herpes simplex virus (HSV) and methicillin resistant Staphylococcus aureus (MRSA) DNA, which all show very poor amplification with normal NASBA, assay sensitivity was improved by a factor 100-1000 when restriction enzyme digestion was performed prior to amplification. For the quantitative HBV assay, in combination with the NucliSENS Extractor (bioMérieux, Boxtel, The Netherlands), a 95% target detection rate of 242 WHO IU/ml and 50% detection rate of 35 WHO IU/ml was achieved.