the basic principles are the same for most cross-linking fixatives and induce similar bonds the difference you observed between may due to any other variability, or the co-fixative you used.
I DO believe that one reason some people use 4% PFA rather 10% formalin is that PFA is a bit more stable, both for storage and transportation~~~. 2008-12-05 tf 发件人： Tony Henwood 发送时间： 2008-12-05 06:00:03 收件人： [EMAIL PROTECTED]; Jan Shivers; histonet 抄送： 主题： RE: [Histonet] IHC on paraformaldehyde-fixed Interesting point. Since 10% buffered formalin (made from the concentrated 38% formaldehyde) contain about 1% methanol, has it been shown that this has a deleterious effect on ANY antigens or are we expecting this worse case senario as being the norm? I am not aware of any antigens (or antigen-antibody combination) that has been badly effected by 10% formalin that is NOT effected by 10% formaldehyde. Are you aware of any?? 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: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Friday, 5 December 2008 1:31 AM To: Tony Henwood; Jan Shivers; histonet Subject: Re: [Histonet] IHC on paraformaldehyde-fixed So true. However, be aware that 10% neutral buffered formalin we use has methanol in it which may affect certain antigens so there may be some difference in staining (hence why for mouse work we now only use 4% PFA in pure PBS). It is good to be aware of the other ingredients in your fixative solutions, whether commercially prepared or a homemaede recipe, as it isn't only the formaldehyde fixative which can make a difference. -----Original Message----- From: Tony Henwood <[EMAIL PROTECTED]> Date: Thu, 04 Dec 2008 09:35:09 To: Jan Shivers<[EMAIL PROTECTED]>; histonet<histonet@lists.utsouthwestern.edu> Subject: RE: [Histonet] IHC on paraformaldehyde-fixed Gee I hate the term paraformaldehyde (as many of you probably know) This is an example of how confusion of terms can cause unnecessary work. Is "4% paraformaldehyde" different from 4 % formaldehyde? No Should any procedure done to tissues fixed in "4% paraformaldehyde" give results different to those fixed in 4% formaldehyde or 10% formalin? No since they are the same thing. As Manoonkitiwongsa and Schultz (Histochem J 34: 365-367, 2002) state when paraformaldehyde actually becomes a fixative, it is no longer paraformaldehyde by chemistry or fixation capacity. Rather, it is formaldehyde in water without methanol or any other stabiliser. Without heat and an alkaline environment, paraformaldehyde in water is simply a paraformaldehyde suspension with little fixation capacity. If the fixative is prepared from paraformaldehyde then it should be termed 4% formaldehyde freshly prepared from paraformaldehyde. If a concentrated formalin solution (40% formaldehyde) is used, then it should be termed 10% formalin. If you do a search on Histonet for paraformaldehye, you will find that this topic has been extensively discussed. 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: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jan Shivers Sent: Thursday, 4 December 2008 8:34 AM To: histonet Subject: [Histonet] IHC on paraformaldehyde-fixed Has anyone ever done IHC on parafomaldehyde-fixed tissues, and if so, how well did it work? Will the same antigen-retrieval methods used with formalin-fixed tissue be applicable? I'm asking for an investigator, who already has his tissues fixed in paraformaldehyde. Jan Shivers Senior Scientist Pathology Teaching Program Histology/IHC/EM Section Head University of Minnesota Veterinary Diagnostic Laboratory 1333 Gortner Ave. St. Paul, MN 55108 612-624-7297 [EMAIL PROTECTED] 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. 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