From: Dr. Eckhard Goernitz <goernitz@iap.fhg.de>
  To  : Olwyn Byron <o.byron@bio.gla.ac.uk>
  Date: Fri, 19 Dec 1997 09:39:37 -0800

Re: PEG

Olwyn Byron wrote:
>

> Hello RASMBers
>

> I've got two quick questions to ask concerning polyethylene glycol
(PEG).
>

> We're trying to characterise a protein-PEG system and are having real
> trouble measuring a vbar for the conjugated molecule. However, we know
the
> mass fraction of PEG and so conceivably we could estimate a vbar if we
knew
> the vbar of the PEG we're using.
>

> So, does anyone have any vbar data for PEG?
> In particular we're after vbar for PEG 5,000, 10,000, 20,000 and
40,000 (Da)
> (I don't know that vbar for these will necessarily be comparable).
>

> The second question concerns labelling PEG: does anyone know of an
easy way
> to covalently (or non-covalently) label PEG (so that we can try AUC
studies
> using absorbance optics)?
>

> Thanks in advance for your responses to these questions.
> All the very best for Christmas and the New Year-
>

> Olwyn Byron.
>

> _____________________________________________________________________
> Olwyn Byron
> Division of Infection and Immunity
> Institute of Biomedical and Life Sciences
> Joseph Black Building, University of Glasgow
> Glasgow, G12 8QQ, Scotland.
>

> tel: +44 (0)141 330 3752  email: o.byron@bio.gla.ac.uk
> fax: +44 (0)141 330 4600  web:   www.gla.ac.uk/Acad/IBLS/II/ob/ob.htm
> _____________________________________________________________________

Dear Olwyn,

I have found some unpublished v-bar-data measured many years ago by Karl
Linow(+) and me for PEG in water at 20°C:

M(PEG) (g/mol)		v-bar (ml/g)

  200				0.862
  400				0.845
  600				0.841
 1500				0.838
 4000				0.836
10000				0.834
20000				0.832

These were in general accordance to results of:
L.Lepori and V.Mollica, J. Polymer Sci. Polym. Phys. Ed., Vol. 16 (1978)
1123-1134

Best regards
Eckhard Görnitz

*******************************************************
Dr. Eckhard Görnitz
Fraunhofer Institut f. Angewandte Polymerforschung
Kantstr. 55, D-14513 Teltow, Germany
Tel: +49(0)3382 46 391
Fax. +49(0)3328 46 344
E-Mail: goernitz@iap.fhg.de
*******************************************************