PEG c.d.

[HELISA]

Hmm, I was thinking that PEG may disturb somehow the lipid bilayer of plasma membrane and may cause formation of pores which in turns may assist in absorption of RNA and DNA molecules from environment. Maybe I am wrong...but it is just my assumption....

[LilKim]

Essentially that's what it would have to do ... for cells to take up large molecules. The membrane would have to be made more permeable that usual.

That's the the mechanism that's used to transform many types of cells (disrupt normal cell surfaces/membranes... making them more permeable... thus allowing uptake of thing not usually taken-up)

But, i'm not sure how excatlly PEG works.. or what cell mem. moeecules it intereacts with. I know that peg was used to fuse cells in prior studies to support the "fluid mosiac" properties of cell membranes.

but that's i guess.. i don't really know much about this stuff anyways

- kim

[LilKim]

Hey!!!

I was in lab today, and one of the reagents that I had to make (to transform yeast cells) contained PEG. So, i asked a lab-mate about the function of PEG. And he told me that he wasn't eactly sure.. but he said that he believed that it functions as a molecular crowder? ... which I guess would increase the concentration of other things in a test tube ...??

anyways, i'm still not sure

[HELISA]

More people...more opinion
I am working in virology lab and I am using two different types of PEG:
1) 8000 molecular weight for virus precipitation (this is how PEG may act as a crowder)
2) 1500 molecular weight to introduce viral RNA into cells (this is how PEG acts as a permeability agent)
But still...how exactly PEG works I have no clue...
What is more, it is added to almost every type of consmetics which I am using shampoons, soaps...
Interesting polymer...!

[2810712]

please see this...I'm feeling neglected

about5991.html

diff. molecular wt.s used for differnt functions ...interesting...does it act as crowding agent for lipids..? proteins? etc? Something like common ion effect..? THere it was charge... here it may be something like steric hindrance..? But acting crowder for both lips & prots at a time increases the chances that it has both kinds of groups- hydrophils & phobes...

please check the above link for my sake.


hrushikesh

[HELISA]

Thank you
I read that...don't feel neglected
All the best!
Helisa

[2810712]

thanks, that was a great relief, now i don't feel neglected!
Waiting for ur opinions & any info u got...






hrushikesh

[biznatch]

I too was looking for the function of PEG 8000, came across this forum topic, then the following product, and thought I'd post it back here:

From USB Corporation, their PEG 8000 product page (I can't post the URL since I have less than 5 posts but Google for USB Corporation then do a Product Search for PEG 8000):

Applications:
•Differential precipitation of DNA.
•Enhances hybridization rate of nucleic acids.
•Improves efficiency of end-labeling with T4 Polynucleotide Kinase(1,2).
•Used in ligation of blunt ended DNA.
•Precipitates bacteriophage ± particles and plasmid DNA.
•Used in preparing single-stranded M13 DNA.
•Promotes cell fusion.

PEG, with magnesium, causes DNA to undergo a “psi” transition and it collapses into a highly condensed state(1). This results in macromolecular crowding(2) and increased efficiency in end-labeling.

References:
1. Lerman, L.S. (1971) Proc Natl. Acad Sci, 68, 1886.
2. Harrison, B. and Zimmerman, S. B., (1986) Anal Biochem, 158, 307.