CitiFluor™ AF4, Mounting Medium, 25ml

Storage and Shelf-Life

The AF4 solution should be stored in brown glass bottles at temperatures between 5° and 15°C and shielded from strong sunlight. The cap of the bottle should always be replaced after use as a matter of good practice and to prevent the absorption of moisture from the atmosphere. Samples stored under these conditions for 12 months, have shown no apparent deterioration and in particular no discoloration. If the AF4 solution is being used in an assay, a control experiment should always be carried out.

Usage and Useful Tips

AF4 is a solution composed of the antifading reagent n-propyl gallate dissolved in glycerol and is optically transparent between 400nm and 750nm.

If the solution is to be used as a mountant solution as supplied, wash the specimen with a buffer of appropriate pH for the fluorochrome label (so as to maximize the fluorescence intensity) and then apply a few drops of AF4.

An aqueous solution (75% AF4 to 25% water v/v) has a pH of ~5. Since many fluorochromes exhibit their maximal fluorescent intensity at higher pH values the AF4 should be mixed with an appropriate buffer solution.

Alternatively, buffer solutions may be added to AF4 to create your own mountant solution. But don’t increase the amount of buffer volume to higher than 30% since this leads to a dramatic reduction in shelf-life.

N-propyl gallate is a well-established antifadent and is particularly useful for stopping photobleaching of DAPI, Hoechst and Alexa dye stained materials as well as FITC labelled materials.

The solution should be pipetted onto the specimen and then a cover slip applied. If the slides are stored in a refrigerator, the viscosity of the mountant solution increases thereby helping to keep the cover slip in place. There is no need to seal the cover slip with nail varnish.