[edgardoodle]

Hello,

How important is the removal of endotoxins, when creating a PEGylated Interferon protein (E Coli is source)? 

Is it a necessary step? 

[jeffmoonchop]

We normally have a limit of <2EU/ml for our products going into NHP and humans. I'm not too familiar with industries that use bacteria as a source of creating proteins, but I'm guessing they will need to remove endotoxin from their product before injection is possible. Its difficult to remove but there are filters designed for this purpose. We normally ensure it doesn't get in in the first place but if you need to use e.coli its unavoidable.

[edgardoodle]

We normally have a limit of <2EU/ml for our products going into NHP and humans. I'm not too familiar with industries that use bacteria as a source of creating proteins, but I'm guessing they will need to remove endotoxin from their product before injection is possible. Its difficult to remove but there are filters designed for this purpose. We normally ensure it doesn't get in in the first place but if you need to use e.coli its unavoidable.

Great, thank you!

I actually have another question, regarding half-life. So, obviously the PEGylation greatly increases the half-life of naked human recombinant interferon proteins. But I was wondering the impact that various PEGylation methods will have on half-life.

From what I have read, it appears that even with different methods of pegylation, the half-life appears to be far greater than before pegylation... and that various methods only have minor affects on the half-life.

Does anyone know if this is true?