Fixation must be adequate before decalcifying. 12-24h in Bouin is OK. My favourite formic decalcifier is that of Clark (1954) Am. J. Clin. Path. 24: 1113-1116. It's a buffer (pH2.0) made by mixing 90% formic acid 250ml, water 750 ml and sodium formate (anhydrous) 34g. Keeps for ever. Check the reference. Never trust a recipe you read on the internet!
The picric acid in picro-sirius red is a necessary component of the staining solution. See Junqueira et al 1979 Histochem. J. 11: 447-455. It's important to have the correct red dye; there is more than one "sirius red". Use C.I. 35780, Direct red 80. John Kiernan London, Canada = = = On 15/04/15, Tyrone Genade <[email protected]> wrote: > Hello, > > Some questions regarding Bouin's solution. > > I was told, back when I was doing my PhD and new very little, that I should > fix my fish in Bouin's as it will decalsify the bones. Well, Bouin's fixed > fish were easier to cut than PFA fixed fish... but I read today that by > adding formic acid the decalsification is better. (I must confess, that > after Buoin's fixation I still had to soak the tissue face in some dilute > nitric acid now and then...) Another reference said that the formaldehyde > should be replaced with formic acid. So which is it: add formic acid or > replace formaldehyde? And if the former, how much do you add? > > Second question: a colleague and I want to stain for collagen in diseased > kidneys. The fixative of choice for soft tissue is Bouin's... But the > staining protocol called for a solution of picric acid and sirius red. Is > the picric acid needed if I haven't washed the picric acid from the Bouin's > fixation out of the tissue? I was told once that the picric acid was for > contrast... Is this BS? Does the picric acid play an important chemical > role in the staining? I would like to avoid the need for a bottle of > saturated picric acid on the lab shelf here in Iowa where the winter low > humidity desiccates everything... I'm hoping this protocol, > http://www.ihcworld.com/_protocols/special_stains/sirius_red.htm , can be > modified to omit the picric acid. > > Thanks > -- > Tyrone Genade > Orange City, Iowa > tel: (+1) 712 230 4101 > http://tgenade.freeshell.org > ******************************************************************************** > Romans 6:23: The gift of God is eternal life through Christ Jesus our Lord. > To find out how to receive this FREE gift visit http://www.alpha.org. > _______________________________________________ > Histonet mailing list > [email protected] > http://lists.utsouthwestern.edu/mailman/listinfo/histonet > > _______________________________________________ Histonet mailing list [email protected] http://lists.utsouthwestern.edu/mailman/listinfo/histonet
