I have been asked about a supplier.  I know of at least 4:

1.  Aldrich                                www.sigmaalldrich.com 
          Fomblin Y  LVAC 14/6        Cat # 317934-100G    100g

2.  Lancaster/Alfa Aesar    
www.alfa.com/CGI-BIN/LANSAWEB?WEBEVENT+L0178567F6B740600C68505B+ALF+ENG
          Fomblin YR-1800                 Item # L17548              5 or 
25g
 
3.  Specialty Fluids              www.vacuumoil.com/fomblin.htm
          Lots of Fomblins             1kg

4.  Hampton Research       
www.hamptonresearch.com/product_detail.aspx?cid=4&sid=138&pid=551
          PFO-X175/08                         Cat # HR2-814 1ml


The price per unit is very different for each supplier, so check it out 
for yourself.

And, if you get into this sort of stuff, the following link has the 
properties and specifications of the different oil types:
http://www.vacuumoil.com/msdspdfs/productinfo/fom_vac.pdf

One additional tidbit:  if you are using this to retard evaporation of a 
volatile organic, consider saturating the oil before placing your crystal 
in the oil or the oil on the drop!  It takes very little to saturate and 
is unlikely to add solvent to the crystal or drop.

Enjoy,
Kris
---------------------------------
Kris F. Tesh, Ph D
Director, Macromolecular Products
Rigaku Americas Corporation
9009 New Trails Drive
The Woodlands, TX  77381  USA
001 281 362 2300 x 144 
----- Forwarded by Kris Tesh/Rigaku on 09/01/2009 03:25 PM -----

From:
Kris Tesh/Rigaku
To:
CCP4BB@JISCMAIL.AC.UK
Date:
09/01/2009 10:33 AM
Subject:
Re: [ccp4bb] cracking crystal


...and I prefer to use PFPE (perfluoropolyether, trade name FOMBLIN) as an 
oil since it is less viscous, has no reactivity and is a low temp 
lubricant that freezes easily.  Small molecule crystallographers have used 
it for years.

Kris
---------------------------------
Kris F. Tesh, Ph D
Director, Macromolecular Products
Rigaku Americas Corporation
9009 New Trails Drive
The Woodlands, TX  77381  USA
001 281 362 2300 x 144 



From:
Leonard Thomas <lmtho...@ou.edu>
To:
CCP4BB@JISCMAIL.AC.UK
Date:
09/01/2009 10:09 AM
Subject:
Re: [ccp4bb] cracking crystal



One thing that I have had work in the past is just increase the 
percentage of PEG.  I think something around 30-35% may work for 
PEG4K, maybe a little higher.   Most PEGS will work as a cryo 
protectant if the concentration is high enough.

Also as mentioned before you could try stepping up  the glycerol 
concentration very gradually.  I had a colleague who said the protein 
he worked on in grad school had to be stepped up 1% increments or it 
would crack and fall apart.  IIRC he had better then 2.0 ang. data for 
the final structure.

Leonard Thomas Ph.D.
Macromolecular Crystallography Laboratory Manager
University of Oklahoma
Department of Chemistry and Biochemistry
620 Parrington Oval
Norman, OK 73019

lmtho...@ou.edu
http://barlywine.chem.ou.edu
Office: (405)325-1126
Lab: (405)325-7571

On Sep 1, 2009, at 5:25 AM, Fengxia Liu wrote:

> Dear All,
>
> Could you please help me solve this problem?
>
> I have a sensitive crystal, the mother liquor is 10% PEG4k+ 100 mM 
> Tris-buffer pH 8.5, crystal is big and good but very sensitive, when 
> i put it in cryoprotectants, cracking happened. First i used 
> artificial mother liquor + 25% v/v glycerol, slowly decrease to + 
> 12.5% v/v glycerol, all crystals cracked after immersed, finally i 
> tried 50% mineral oil + 50% paratone, it still cracked (4- 5 cracks, 
> but not broken) . even this cracked crystal can give me 3.2 angstrom 
> diffraction, so no cracked crystal might give me 2.0+ angstrom 
> diffraction. Now i don't have many crystals to try so many 
> cryoprotectants, so anybody has experience on this? any suggestion 
> would be greatly appreciated.
>
> Thank you.
> Fengxiale



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