Re: [Histonet] Question about molecular sieves for EtOh
In a message dated 8/15/2006 6:04:23 PM US Mountain Standard Time,
> Today I added 3A bead molecular sieves to my EtOh, so I can have
> (hopefully) a better tissue dehydration tomorrow. But the ethanol took on
> quite a murky appearance. It seemed that after a few hours it cleared, just
> a tiny bit. But it still looks kind of scary.
> Does this go away completely -- with longer sitting of the ethanol??? Or
> does anybody know a good way to separate, without the chance of humidity
> getting back into the EtOh?
> Thanks so much.
I've used 5A molecular sieve in ETOH for the same purpose, and I got exactly
the same result: cloudy ETOH.
The cloudiness does go away after a couple of days and the sediment will
collect on the bottom of the bottle. I think it must be the result of small
pieces of molecular sieve coming off the pellets.
I always played it safe...letting the ETOH stand for a couple of days, then
carefully removing or decanting from the top to use it.
I also tried filtering the ETOH in a syringe with a luer-lok Millipore filter
(0.4 micron pores, if I remember correctly) attached to the syringe, but
honestly I could see no difference between decanting and filtering. Both kinds of
ETOH worked fine, and I never saw any kind of "crud" in my specimens.
I used the ETOH for electron microscopy specimen prep, so you'd think the
precipitate would certainly be visible if it was present. But I never had any
I also used this technique to keep acetone anhydrous. It worked like a
Hope this helps.
Robert (Bob) Chiovetti, Ph.D.
The Microscope Works
Arizona's Microscopy Resource
132 North Elster Drive
Tucson, AZ 85710-3212 USA
Member, Arizona Small Business Association - ASBA
Histonet mailing list
<< Previous Message | Next Message >>