[3dem] prepare Formvar Grids

[Patricia Grob]

Hi Denis,

We were having the same problem getting Formvar to come off so called "pre-cleaned" glass slides for a while. We tried a lot of black magic in desperation (one protocol included "pizza breath" or "garlic breath") until we found one technique that has been 100% foolproof in our hands:

Before dipping glass slides into Formvar solution (for us it works both for 0.5% Formvar in chloroform or 0.5% Formvar/chloroform with 50% glycerol droplets in suspension - used for holey films):

- Dip entire glass slide into pure ethanol or methanol beaker for a few seconds (it may also work with other solvents but those are the only ones we have used so far)
- take slide out, wipe off excess solvent with Kimwipes. 
- Repeat last two steps if you still see streaks on glass
- blow lint off with compressed air if needed
- let slide finish drying for 2-5 min

Make sure to float the Formar off within 1/2 hr of cleaning!

 we then proceed as follows:

- dip clean glass slide into Formvar solution, blot edges on filter paper, let dry (a few minutes are sufficient). Again, use within 1/2 hr!
- score edges with new razor blade
- enter slide at 45 degree into clean (Millipore) water to float Formvar film off glass.

I hope this will work for you as well.
Cheers,

Patricia





On Sep 28, 2012, at 1:36 AM, Peter Engelhardt <Peter.Engelhardt at Helsinki.Fi> wrote:

> Hi Dennis,
> 
> We use simple almost "magic" foolproof method - originally shown by Jan Derksen visiting our lab in1970ties.
> 
> - Polish slides with a clean cotton towel extensively that is all corners etc 
> - Ready when you experience that the slide appears more slippery after polishing - might take some time.
> - Blow away the lint that might appear.
> - Proceed instantly accordingly to any of the protocols presented.
> 
> The procedure helps when the air is very dry - e.g.in winter time
> and in labs for cryo-EM works where the humidity is kept purposely low.
> 
> Let's hope this trick helps
> 
> Cheers
> Peter
> 
> 
> On Sep 27, 2012, at 11:30 PM, Denis Chaix wrote:
> 
>> Hello
>> We have actualy some troubles to prepare Formvar films.
>> In fact it's impossible to release the film from the glass slide.
>> Here you can find our protocol
>> 
>> Formvar solution. 0,4% in chloroform .
>> Pour the solution into a clean Coplin jar
>> Dip pre-cleaned slides ( rub thoroughly with Kimwipes) into beaker.
>> Drain corner on side of beaker.
>> Blot edge of slide on filter paper.
>> Score the edges of the Formvar film with an acetone-cleaned razor blade.
>> Breathe over the length of the slide to loosen the film.
>> Float the film off onto a clean water surface by slowly immersing the slide into the water at a 45° angle.
>> 
>> 
>> Have you some tricks or tips to improve this protocol and help the release of the film ?
>> For example, have you some ideas like special brand of slides, or a way to clean the slides.
>> 
>> Thanks
>> 
>> 
>> 
>> Denis
>> -- 
>> --
>> ____________________________________________________________________________
>> _______________
>> 
>> Chaix Denis <denis.chaix at ibs.fr>
>> Microscopie Electronique et Méthodes
>> <http://www.ibs.fr/groupes/groupe-microscopie-electronique-et/>
>> Room 6234
>> Institut de Biologie Structurale UMR-5075 <http://www.ibs.fr/spip.php>
>> 41 Rue J. Horowitz
>> 38027 Grenoble Cedex 1,France
>> Tel: +33.4.38.78.01.59.
>> Fax: +33.4.38.78.54.94.
>> ____________________________________________________________________________
>> _______________
>> 
>> _______________________________________________
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> 
> _________________________________________________________
> Peter Engelhardt, PhD, docent
> Adjunct Professor in Molecular Genetics
> Unit of Molecular Electron Tomography
> 
> Department of Pathology
> Haartman Institute
> P.O.Box 21, FI-00014 Univ. of Helsinki, Finland
> Visiting Address: Haartmaninkatu 3, Helsinki
> 
> Nanomicroscopy Center (NMC ), Department of Applied Physics
> Aalto University, School of Science and Technology,
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> Finland
> 
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> 
> Mobile:  +358-(0)400193342
> Email: Peter.Engelhardt at Helsinki.Fi
> URL: http://www.lce.hut.fi/~engelhar/
> 
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_______________________________
Patricia Grob, Ph.D.
Research Specialist
Nogales Lab
HHMI at UC Berkeley
Molecular & Cell Biology Department / QB3,
Stanley Hall #742
University of California, Berkeley
Berkeley, CA 94720-3220
Phone: (510)666-3335	Fax: (510)666-3336
E.M. suite B307: (510)666-3339
URL: cryoem.berkeley.edu
Email: pgrob at berkeley.edu



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