Re lambda preps

Antje Haase antje at RT1.MENZIES.SU.EDU.AU
Fri Jul 30 18:50:51 EST 1993


> 
>  
> 
> I was always under the impression that the flakes floating around are the
> chromosomal DNA strands that have been released from the cells.  
> I realize that proteins may make more bulk than DNA in a culture, 
> I cannot seem to think of any reason why  would coagulate or form flakes.
> Whereas the DNA might form flakes beacuase the integrity of the chromosome
> has been destroyed.  I have seen similar flakes in isolating intracellular
> microorganisms such as rickettsia.  The flakes look very similar to 
> that seen in lambda preps.  We used to prevent these from happening
> by incubating the lysate with DNAseI, which used to make it convenient
> for renografin gradient centrifugation.  
> 
> If you have any thoughts, I would appreciate hearing from you.
> Regards.
> Raj Shankarappa
> bsh at med.pitt.edu
> >

Hi Raj,

the proteins that are released from lysed cells will definitely form flakes
becuase many of them are very hydrophobic and often probably still integrated
into membranes.  So they obviously will try and avoid the aqueous environment
as much as they possibly can which means aggregate with other hydrophobic
proteins which will result in the flakes. 

Cheers
 
Antje  
> >  
> >  
> >  
> >  __________________________________________________________________________ Antje Haase
Menzies School of Health Research
antje at menzies.su.edu.au
 Australia
> >  _________________________________________________________________________>  
> >  
> >  
> > 
> > 
> 
> 




More information about the Methods mailing list