so I see a change in the analytical methods for XBB 1.5 and Omicron 2024 versions
Originally, RNA content was assessed with RT-PCR (table 3.2.S.3.6)
But for these new variants they are testing with ddPCR in ANDOVER (US) but still using RT-PCR in Mainz
Why? Are they considered equivalent? I am not sure.
But I am pleasantly surprised that they are measuring the poly (A) tails using IP-RP-HPLC. This method is the one that USP (and maybe Ph. Eur) are recommending to be the compendial standard. The ddPCR for poly (A) tails never made sense. No one can tell me why Pfizer did this.
so I see a change in the analytical methods for XBB 1.5 and Omicron 2024 versions
Originally, RNA content was assessed with RT-PCR (table 3.2.S.3.6)
But for these new variants they are testing with ddPCR in ANDOVER (US) but still using RT-PCR in Mainz
Why? Are they considered equivalent? I am not sure.
But I am pleasantly surprised that they are measuring the poly (A) tails using IP-RP-HPLC. This method is the one that USP (and maybe Ph. Eur) are recommending to be the compendial standard. The ddPCR for poly (A) tails never made sense. No one can tell me why Pfizer did this.
They blacked-out all the data. But many thanks!