Tamara
howard@cshl.org

Tamara: it works ok, but removing them from the eppenddorfs can be tricky sometimes. Also, if your pellets are too dense, poor infiltration and polymerization can be a problem.

Why not embed them in agar first in the tubes then transfer them..> > >

Hank Adams, NM
hadams@nmsu.edu

Just wanted to point out that the term "Eppendorf tube" is a bit like "whiskey", understood instantly, but in fact refering to a wide range of product. So, "ep tubes" are made by gazillions of companies and presumably out of, well, dozens, of different kinds of plastics. Might be worth finding out from someone in the successful camp exactly where they bought their ep tubes.

Tobias I. Baskin
baskin@biosci.mbp.missouri.edu

This is a good point. For consistently good results, we use "real" Eppendorf tubes, i.e. made by Eppendorf. We did have problems with slightly cheaper ones once, though I've forgotten exactly what the trouble was.

Rosemary White
email rgwhite@vaxc.cc.monash.edu.au

Dear Tamara
I have used LR White in three sizes of Eppendorfs (0.5, 1 & 2ml or thereabouts). Air did not seem to be a problem, but the plastic used in the tubes must have reacted with the resin. The smallest size tube resulted in strangely shaped blocks, the bigger ones seemed ok. I didn't persue the matter, but I could imagine that coating the inside of the tubes with gelatine might help preventing any reaction (I also used gelatine capsules inside Eppendorfs which worked very well). Hope this helps

Dr Stephan Helfer
S.Helfer@rbge.org.uk

No plastic capsule or tube that I know of is air-tight enough for LR White.You may double emded with gelatin and get away with a plastic capsule.

Kate Connolly
Katherine.S.Connolly@Dartmouth.EDU

The following was posted recently:

No plastic capsule or tube that I know of is air-tight enough for LR White.You may double emded with gelatin and get away with a plastic capsule. Kate Connolly

Standing in our exhibit booth, and listening to how some of our more ingenuous customers use some of our products, I have learned that if one takes the UV transparent SPI embedding (silicone) molds, and over fills them slightly, and then places another (identical) mold on top, the capillary action between the two molds really does seal out oxygen to the point that the resin can be UV cured without worry that oxygen will some how interfere.

Of course, after polymerization, the top mold separates easily and the blocks are removed from the "bottom" mold.

There are a number of advantages to using this approach since it is far more easy to properly align samples in a specific direction with respect to what will eventually become the cutting direction.

More information about the SPI Supplies silicone embedding molds can be found in our electronic catalog on the WWW (see below).

Charles A. Garber, Ph. D.
GVKM07A@prodigy.com

We routinely used LR White some years ago for embedding of bacteria. It worked well with 0.5 ml Eppendorfs. But: some Eppendorfs were better, some worse; I guess that there are various brands of 0.5 ml cups on the market, made by different manufacturers with different plastics and plasticizers; some of them may interfere with the hardening of the resin. We also observed (as already mentioned) that the top part (1 - 2 mm) of the resin has not hardened. (oviously, the air does interfere with the hardening process).

Reinhard Rachel
Reinhard.Rachel@biologie.uni-regensburg.de

Just a quick note on LR White embedding: We occasionally use flat embedding with LR White into polyethylene (I believe) molds and cover the whole thing with Saran wrap. It is a bit messy but it works. I believe you could overfill the tube sligthly and cover with Saran wrap too. Cheers,

Sarka Lhotak
lhotaks@fhs.mcmaster.ca

What I should have said was polypropylene Eppendorf-type tubes work fine. Fisher Scientific and USA Scientific make the ones we use. We use doggie toenail clippers to snip off the end of the tube and then tease or cut out the polymerized sample and remount it for trimming and sectioning. If the whole embedding process takes place in the tube, take care to see that there is good exchange of fluids at the bottom of the tube or else you could have trouble.

I have never drunk any whiskey from them however.

Greg Erdos
E-mail: gwe@biotech.ufl.edu