HIGHLY SENSITIVE DETECTION OF GENE-EXPRESSION OF AN INTRONLESS GENE -AMPLIFICATION OF MESSENGER-RNA, BUT NOT GENOMIC DNA BY NUCLEIC-ACID SEQUENCE BASED AMPLIFICATION (NASBA)

NASBA is an isothermal nucleic acid amplification reaction that amplif ies mRNA in a dsDNA background. Although similar to the sensitive reve rse transcription/polymerase chain reaction (RT-PCR) in mRNA detection , NASBA is not prone to give false positive results caused by genomic dsDNA. Therefore, NASBA is unique for sensitive detection of transcrip tion of intronless genes, which preclude strategies such as intron spa nning primer pairs to control false positive results in RT-PCR. Using NASBA, mRNA of the intronless human interferon-beta gene was demonstra ted with a sensitivity of 10 copies, whereas 100 ng genomic DNA gave a negative result.