inclusion bodies and color

[Michael Witty]

Dear S.Ballal,
             I found this too.  At the time I assumed it was black bits of
carbonized tryptone or yeast extract from the manufacturing process or
from my own autoclaving - this helped me ignore the black layer.  Mike.

On 16 Dec 2001, S.Ballal wrote:

> Hi everyone!
>
> While isolating inclusion bodies from E.coli for a expressed proteins
> we are getting some black colored layer around the inclusion body
> pellet.
>
> It is not from the medium as the cell pellet is free from such color
> and is normal whiteish brown.  There seems to a difference in the
> quantity of color formation depending upon the source of Yeast extract
> and tryptone also.
>
> I would like to know if any other group is also having similar results
> and possible reasons for it and of course if it due to oxidation of
> proteins how to get around such a situation
>
> thanks,
>
> S.Ballal
>