sealing slides on VDX plates?

From: Dima Klenchin
Date: 18 November 2011 17:55

Hello,

I wonder what everyone is using for sealing hanging drop slides on VDX plates? For the most part, we paraffin oil but I am unhappy with it because it is too think and too frequently there is break in the oil and the drop dries too much. I find vacuum grease to be not terribly practical because it takes too much time - particularly when the well needs to be opened (seeding, modifying well content, etc).

In ideal world I would like to find a much thicker oil that 1) contains as little volatiles as paraffin oil, and 2) allows no more water vapor diffusion through it than paraffin oil. Hampton suggests Cargille immersion oils for this purpose but the MSDS for these oils states that they have slight odor, so I am a bit concerned with unknown volatiles getting into crystallization drop.

So, what do you like to use? Thanks much,

- Dima

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From: Bosch, Juergen

Dow Corning Heavy Vacuum Grease, a 10 ml syringe and a shorter cut 200 µl tip attached to the syringe.

Jürgen

......................

Jürgen Bosch

Johns Hopkins University

Bloomberg School of Public Health

Department of Biochemistry & Molecular Biology

Johns Hopkins Malaria Research Institute

615 North Wolfe Street, W8708

Baltimore, MD 21205

http://web.mac.com/bosch_lab/

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From: <malhotra


Vaseline (pure, with no additives) from CVS/Walgreens in a 10 ml syringe and a pipette tip (wide bore) also works very well.

--
Arun Malhotra                                                 
Associate Professor   

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From: Prince, D Bryan


I remember a technique that used warmed Vaseline (liquefied) in a shallow pan. People would invert the plate and dip it into the liquefied Vaseline, then flip it over to dry. I suppose one could use masking tape to cover the outer edge of the plate to keep it Vaseline free. I am not sure how it would work with cryschem (24-well sitting drop) plates.

Good luck!
Bryan



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From: Christopher Browning


The is probably the cleanest and fastest way of greasing plates.

Take a 15ml Falcon tube and unscrew the cap. You will notice that the cap is exactly the width as the well of the VDX plate. Using a fairly wide bored metal syringe needle, pierce 8 holes into the cap from the outside, along the top edge of the cap. Fill the Falcon tube with Vaseline and screw the cap back onto the tube. Loosen the cap about 2 to 2.5 turns, just before it comes of the tube. Stick the tube in a heating block, wait for the Vaseline to melt. When you now invert the tube with the liquid Vaseline, it should not come running out, but if you press the top of the cap against the well of the VDX plate, you will see that a small amount of Vaseline is let out through the small holes. If you lift the tube off the well, air will then go into the tube and you can press the cap against the next well. Continue until you're. Should take no more than a few seconds to do the whole plate.

Cheers,

Chris Browning

--
Dr. Christopher Browning
Post-Doctor to Prof. Petr Leiman
EPFL
BSP-416
1015 Lausanne


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From: Patrick Loll


Haven't done this for a while, but what we used to do was mix Vaseline plus mineral oil (both purchased for cheap at the local drugstore), and then apply it using a 10 ml syringe with a pipet tip attached.

We used the mixture of Vaseline + mineral oil because Vaseline alone is too viscous (unless you want to develop Popeye forearms).

Heat a jar of Vaseline in a hot water bath (NOT OVER A FLAME--it's flammable!) until it melts. Mix in about 10-20% mineral oil by volume (you can play with this ratio until you find the viscosity you like); then draw the mixture up into syringes while still liquid. The procedure a little messy, so fill a lot of syringes at once and you're set for years.

Pat

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From: Kay Perry


I have used melted Vaseline and a 10mL Erlenmeyer flask.  The mouth of the Erlenmeyer is the same size as the opening of the VDX plate.  Dip flask mouth in melted Vaseline, then press the mouth of the flask onto the opening of the VDX plate.

--
Kay Perry
NE-CAT
9700 S. Cass Ave.
Bldg. 436 E007
Argonne, IL 60439