Bonnie,
		make your own cork discs using fine cork sheeting from
local hardware
store and cutting the discs using a large cork borer. Cheaper than ones we
used to buy. Must use fine cork sheeting as if the cork pieces in the sheet
are large there are usually spaces and these trap nitrogen ....this results
in exploding cork discs when specimens are removed from nitrogen storage.
Barry

At 02:54 PM 7/1/99 -0500, you wrote:
>This sounds good now where do you order the corks????
>
>> -----Original Message-----
>> From:	Tim Fairchild [SMTP:timf@cyllene.uwa.edu.au]
>> Sent:	Thursday, July 01, 1999 3:14 AM
>> To:	HistoNet Server
>> Subject:	Freezing muscle sections
>>
>> We have recently undertaken a project which required a portion of muscle
>> to be analysed for fibre type and oxidative capacity.  The technique we
>> adopted to freeze the muscle (human muscle), was to mount the muscle on
>> cork using 'gum tragacanth', and then freezing this in isopentane cooled
>> in liquid nitrogen.  The trouble we're having is that every 5th sample
>> (roughly speaking) has ice crystal artifact through it.  I am
>> attributing this to the isopentan not being cold enough.  I guess my
>> questions therefore are:
>>
>> 1. Is there a way to protect the muscle from the freezing process, i.e.
>> putting O.C.T. over the muscle?
>> 2. If the muscle has to be frozen in isopentane, what 'set up' has
>> worked for other people (i.e. we put the isopentane in a long metal
>> cylindrical container, inserted in a larger container holding liquid
>> nitrogen) and what techniques have you found useful (e.g. hold in
>> isopentane for 20 seconds)?
>>
>> Any help (or small tips) would be very much appreciated!
>>
>> Thanks in advance,
>>
>> Tim Fairchild.
>> -----------------------------------------------------------------
>> Timothy J. Fairchild B.Sc. (Hons)
>> PhD Candidate
>> Co-ordinator for Centre of Athletic Testing
>> Department of Human Movement and Exercise Science
>> Nedlands, Western Australia 6907
>> Telephone: (+61 8) 9380 2793
>> Facsimile:  (+61 8) 9380 1039
>> Email: timf@cyllene.uwa.edu.au
>> http://www.general.uwa.edu.au/~hmweb/index.htm
>>
>>
>>
>
>