POLYMERASE-CHAIN-REACTION AND VIRAL SAFETY OF PLASMA PRODUCTS - A MANUFACTURERS VIEW

Background: In October 1995, genome amplification techniques have been introduced as an additional step to improve viral safety of products prepared from plasma pools of the manufacturer Immune, Austria. Materi al and Methods: Individual samples corresponding to plasma donations a re ultracentrifuged and the pelleted material is extracted by acid gua nidinium thiocyanate-phenol-chloroform. Reverse transcription and ampl ification are performed in one tube using rTth polymerase. For purific ation of HBV-DNA, pelleted virus is digested by proteinase K. For impr oved specificity, a modified Tag polymerase is used. Tests are perform ed on a pool of aliquots before actually pooling the plasma donations. Amplicon is detected after PAGE by laser-induced fluorescence. Numero us quality-control procedures are described. Results: A total of 1,786 ,250 donations were screened. 36 donations were found HCV-PCR-positive without being anti-HCV-positive, and 2 donations were found HBV-PCR-p ositive without being HBsAg-positive. Conclusion: PCR of plasma pools can efficiently eliminate window-phase plasma donations before pooling .