[Histonet] longterm storage of tissue samples in 70% Ethanol

[Kruttwig, Klaus]

Dear All,

thank you very much for your replies. It's exactly the point that embedding is quite expensive and my tissue collection is growing. Also another reason is that I have seen a couple of papers stating that antigenicity loss in formalin-fixed paraffin-embedded tissue is also not guaranteed and some protein degradation can occur. As a result
I thought storing in 70% EtOH might be better...
I was really thinking about publishing a paper on it, as Rene suggested, maybe including two methods of antigen retrieval conditions.
________________________________
From: Rene J Buesa [rjbuesa <@t> yahoo.com]
Sent: Wednesday, September 18, 2013 8:12 AM
To: Miller, Caroline
Cc: Kruttwig, Klaus; histonet <@t> lists.utsouthwestern.edu
Subject: Re: [Histonet] longterm storage of tissue samples in 70% Ethanol

Caroline:
I see your point and it is not infrequent that tissues are stored in 70EthOL for long periods but, as far as I know, there are no studies on the subject.
Since you are in the field of research why don't you do an experiment?
You could take different types of tissues, the most used perhaps, an fix them under optimal conditions. Then immediately process 1 piece of each and store it included in paraffin. The rest store them in 70EthOL and process one piece monthly during the first year; bimonthly during the second and quarterly during the third year.
At the end make sections of each one and evaluate the epitope signal and characteristics.
You may come up with a very interesting paper to publish and solve this long lasting problem.
Just an idea.
René J.

From: Caroline Miller <cmiller <@t> gladstone.ucsf.edu>
To: Rene J Buesa <rjbuesa <@t> yahoo.com>
Cc: "Kruttwig, Klaus" <Klaus.Kruttwig <@t> ucsf.edu>; "histonet <@t> lists.utsouthwestern.edu" <histonet <@t> lists.utsouthwestern.edu>
Sent: Wednesday, September 18, 2013 10:43 AM
Subject: Re: [Histonet] longterm storage of tissue samples in 70% Ethanol

Sometimes in the research field or is necessary to store up samples without processing, either waiting for other samples from the set, or the cost to the researcher of processing tissue that they might not need

We always advise our users to fix adequately and then store in 70% until they process. We have never had a problem with this, even when samples have been stored like this for months

The theory is that there is just enough alcohol to prevent dehydration or rehydration and it is in 'steady state'

Any concrete evidence to this fact would be greatly welcomed though, I am going on completely empirical evidence!

Yours
Caroline

Caroline Miller
Gladstone Institutes
www.gladstoneinstitutes.org

Tel: 415 7342566
Cell: 415 2187297




On Sep 18, 2013, at 7:21 AM, Rene J Buesa <rjbuesa <@t> yahoo.com<mailto:rjbuesa <@t> yahoo.com>> wrote:

> Why do you have to store fixed specimens for that long? If you are going to process them anyway, why don't you just process them and store as paraffin blocks? It will be much safer and you can be sure of the antigens preservation.
> René J.
>
>
> ________________________________
> From: "Kruttwig, Klaus" <Klaus.Kruttwig <@t> ucsf.edu<mailto:Klaus.Kruttwig <@t> ucsf.edu>>
> To: "histonet <@t> lists.utsouthwestern.edu<mailto:histonet <@t> lists.utsouthwestern.edu>" <histonet <@t> lists.utsouthwestern.edu<mailto:histonet <@t> lists.utsouthwestern.edu>>
> Sent: Tuesday, September 17, 2013 6:52 PM
> Subject: [Histonet] longterm storage of tissue samples in 70% Ethanol
>
>
> Dear all,
>
> I have a question about longterm storage of histology samples and was wondering if someone can help me.
> I am not sure if my current sample storage system is optimal in terms of antigen- and histology preservation. Do you think it is okay to store 4% paraformaldehyde fixated samples before paraffin embedding for approx 2-3 years in 70% EtOH at 4 degree celsius? Or do I risk a decrease in specimen quality?
>
> Any help will be highly appreciated.
>
> Thanks,
> Klaus
>
> Klaus Kruttwig
> Department of Cell and Tissue Biology
> University of California - San Francisco
> San Franscisco, CA, USA
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