[ccp4bb] Fw: [ccp4bb] cracking crystal

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CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

Previous message:
Subject: Absorption Correction
From: James Stroud xtald00d {- at -} GMAIL {- dot -} COM
Date: 2009-09-01

Next message:
Subject: Re: Fw: cracking crystal
From: Kris Tesh Kris {- dot -} Tesh {- at -} RIGAKU {- dot -} COM
Date: 2009-09-01

Subject: Fw: cracking crystal
From: Kris Tesh Kris {- dot -} Tesh {- at -} RIGAKU {- dot -} COM
Date: 2009-09-01

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
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

lmthomas@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

CCP4bb navigation

CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

Previous message:
Subject: Absorption Correction
From: James Stroud xtald00d {- at -} GMAIL {- dot -} COM
Date: 2009-09-01

Next message:
Subject: Re: Fw: cracking crystal
From: Kris Tesh Kris {- dot -} Tesh {- at -} RIGAKU {- dot -} COM
Date: 2009-09-01