Liquid nitrogen (-196C) and nitrogen slush (-207) are the coldest cryogens used, but they have the slowest freezing rates. The most effective cryogens are those that are those that stay a liquid when cooled almost to the temperature of liquid nitrogen.
Propane (-189.6C mp) or Ethane (183.5C mp) is the cryogen of choice that we use for cryo electron microscopy. Margaret E. Bisher Electron Microscopy & Histology Core Facility Manager Department of Molecular Biology Princeton University Moffett Laboratory, Room 113 Princeton, New Jersey Office: (609) 258-7026 Fax: (609) 258-8468 mbis...@princeton.edu On 12/16/08 10:02 PM, "Tony Henwood" <antho...@chw.edu.au> wrote: > Depends on how you freeze. > When we freeze tissue in liquid nitrogen, the tissue is shaken, ensuring > that the gas layer is broken up. > And in so doing we have not seen evidence of ice crystal formation. > > I can send you a reprint of a paper that describes the effect of storage > of brain tumours in saline prior to freezing (causing much distortion of > the tumour) verses receiving the samples fresh on damp gauze or card. > The pics show the evidence. > > Henwood, A., (2007) "Adverse effect of saline on brain intraoperative > (frozen section) Histology" J Histotechnol 30(3):193 > > Regards > > Tony Henwood JP, MSc, BAppSc, GradDipSysAnalys, CT(ASC) > Laboratory Manager & Senior Scientist > Tel: 612 9845 3306 > Fax: 612 9845 3318 > the children's hospital at westmead > Cnr Hawkesbury Road and Hainsworth Street, Westmead > Locked Bag 4001, Westmead NSW 2145, AUSTRALIA > > > > > -----Original Message----- > From: Markus F. Meyenhofer [mailto:mi...@superlink.net] > Sent: Wednesday, 17 December 2008 1:47 PM > To: Tony Henwood; Dana Settembre; carmen loiselle; pathology education > Subject: Re: [Histonet] Isopentane > > > Isopentane is cooled by liquid N2! > To freeze tissue direct in LN2 is not the best way to freeze tissue due > to > the Leidenfrost effect, creating an insulating gas layer between the > tissue > and the liquid and delaying the speed of freezing = an increase in ice > crystal formation. > Regards, > Markus F. Meyenhofer > > ----- Original Message ----- > From: "Tony Henwood" <antho...@chw.edu.au> > To: "Dana Settembre" <sette...@umdnj.edu>; "carmen loiselle" > <carmen_loise...@hotmail.com>; "pathology education" > <histo...@pathology.swmed.edu> > Sent: Tuesday, December 16, 2008 6:19 PM > Subject: RE: [Histonet] Isopentane > > > Try liquid nitrogen > > Regards > > Tony Henwood JP, MSc, BAppSc, GradDipSysAnalys, CT(ASC) Laboratory > Manager & Senior Scientist > Tel: 612 9845 3306 > Fax: 612 9845 3318 > the children's hospital at westmead > Cnr Hawkesbury Road and Hainsworth Street, Westmead > Locked Bag 4001, Westmead NSW 2145, AUSTRALIA > > > > > -----Original Message----- > From: histonet-boun...@lists.utsouthwestern.edu > [mailto:histonet-boun...@lists.utsouthwestern.edu] On Behalf Of Dana > Settembre > Sent: Wednesday, 17 December 2008 5:27 AM > To: carmen loiselle; pathology education > Subject: Re: [Histonet] Isopentane > > > Hello Carmen, > Sorry I have no alternative. I know most labs use that. > When I worked in a neuropathology lab the isopentane was kept in the > refrigerator - an explosion proof one. I believe that means there's no > lightbulb inside and no inner working of a lightbulb inside either. > > > Dana Settembre, HT ASCP > Immunohistochemistry Lab > UMDNJ - University Hospital > Newark, NJ USA > > >>>> carmen loiselle <carmen_loise...@hotmail.com> 12/16/08 12:24 PM >>>> > > Hello , > > I currently work in a neuromuscular lab and all muscle biopsies received > should be cut frozen, no formalin fixed tissues. My concern though, is > to work with isopentane , a well known excellent heat conductor but also > it has the bad reputation of being very explosive. In fact , I've been > told that few years ago, a lab close by of where I work , did explode > because of this solution. Is there , in your knowledge, any other > chemical we can use as replacement and that give as good results. > > Any input will be greatly appreciated > > Merry XMas to all and happy New Year > _________________________________________________________________ > > _______________________________________________ > Histonet mailing list > Histonet@lists.utsouthwestern.edu > http://lists.utsouthwestern.edu/mailman/listinfo/histonet > > _______________________________________________ > Histonet mailing list > Histonet@lists.utsouthwestern.edu > http://lists.utsouthwestern.edu/mailman/listinfo/histonet > > ********************************************************************* > This email and any files transmitted with it are confidential and > intended > solely for the use of the individual or entity to whom they are > addressed. > If you are not the intended recipient, please delete it and notify the > sender. > > Views expressed in this message and any attachments are those of the > individual sender, and are not necessarily the views of The Children's > Hospital at Westmead > > This note also confirms that this email message has been > virus scanned and although no computer viruses were detected, The > Childrens > Hospital at Westmead accepts no liability for any consequential damage > resulting from email containing computer viruses. > ********************************************************************** > > > _______________________________________________ > Histonet mailing list > Histonet@lists.utsouthwestern.edu > http://lists.utsouthwestern.edu/mailman/listinfo/histonet > > > ********************************************************************* > This email and any files transmitted with it are confidential and intended > solely for the use of the individual or entity to whom they are addressed. If > you are not the intended recipient, please delete it and notify the sender. > > Views expressed in this message and any attachments are those of the > individual sender, and are not necessarily the views of The Children's > Hospital at Westmead > > This note also confirms that this email message has been > virus scanned and although no computer viruses were detected, The Childrens > Hospital at Westmead accepts no liability for any consequential damage > resulting from email containing computer viruses. > ********************************************************************** > > > _______________________________________________ > Histonet mailing list > Histonet@lists.utsouthwestern.edu > http://lists.utsouthwestern.edu/mailman/listinfo/histonet _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet