Overview Hardening Mountants Selection Guide


Hardening mountants are aqueous solutions containing a polymer such a poly (vinyl alcohol) (PVOH). When a few microliters of these solutions are pipetted onto a microscope slide and a coverslip applied, evaporation of water slowly takes place and the formation of a stable film results which immobilizes the coverslip.


A variety of hardening mountants is available which provide films possessing a range of hardness. They are based on water-soluble polymers such as poly (vinyl alcohol (PVOH) and poly (vinyl pyrrolidone) (PVP).


Why are aqueous glycerol solutions of PVOH containing antifadents inherently unstable?


PVOH is produced by hydrolysis of poly(vinyl acetate) and most commercial samples of PVOH contain residual (unhydrolyzed) acetate groups. These groups undergo hydrolysis, often accelerated by the added antifadents, during storage and this can cause a change in pH and more usually gellation.


This latter process leads to an unpredictable shelf-life. By making up small volumes of PVOH solution containing the required amount of antifadent solution, you have materials of consistent composition and performance as well as making better use of your purchased materials.


Glycerol Based n


n


AF200 is a glycerol solution containing an amine-based antifadent.


AF300 is a glycerol solution containing a phenolic type of antifadent.


Film Forming Polymer Solutions n


Tris-MWL 4-88 is a classical, popular mountant solution based on Mowiol®


4-88, glycerol, water


and tris-amine buffer. Following evaporation of the water a film of weak to medium strength is formed. To have effective reduction in


Citifluor Hardening Antifadents Glycerol Based


Tris MWL 4-88 + AF200 Tris MWL 4-88 + AF300 CFPVOH + AF200 CFPVOH + AF300


n


photobleaching, it should be used with either AF100, AF200 or AF300.


n


CFPVOH is an aqueous solution of poly (vinyl alcohol) and is designed to be used with the glycerol-based antifadent solutions AF200 or AF300. Following evaporation of the water films of medium hardness are produced.


Glycerol Free n


PVP plus antifadent is an aqueous solution of poly (vinyl pyrrolidone) containing an amine- based antifadent. The solutions are stable over long periods e.g. in excess of five years.


CFPVOH plus antifadent is an aqueous solution of a carefully selected PVOH containing an amine-based antifadent and has a shelf life 6 months.


Film Forming Polymer Solutions n


CFPVOH is an aqueous solution of poly (vinyl alcohol). Retardation of photobleaching is effected by the addition of the aqueous antifadent solution AF100. (1 part AF100 to 9 parts CFPVOH)


Glycerol Free PVP + Antifadent


CVPOH + Antifadent CFPVOH + AF100


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