Prolong Gold Antifade Reagent From Molecular Probes (Invitrogen)

Prolong Gold Antifade Reagent is a mounting medium designed specifically for immunofluorescently labeled samples. It is an improved version of the Prolong Antifade Reagent. The manufacturer made a real effort to significantly simplify handling of this mounting medium. No more squirting of very viscous reagent #1 into a small opening of the bottle with the powdered reagent #2, followed by finger-numbing vortexing, and tedious bubble removal. Now, just “Drop N’ Go”. Drop a watery droplet of Prolong Gold Antifade Reagent from the bottle directly onto a slide, cover it with the cover slip and go home. The mounting process can’t be simpler.

I use Prolong Gold Antifade Reagent in immunofluorescent applications of two types: 1) to mount different types of cells grown as monolayers, 2) to mount free-floating tissue sections. In either case, at the final steps of staining, I use different combinations of immunofluorescently tagged secondary antibodies, which need to be mounted in a medium preserving their fluorescence. After mounting, I go back over and over again to the same slides, to collect more and more images over the period of days or even months. Thus, the use of antifade, quenching medium, which will keep the quality of the fluorescent signal truly stable, is necessary. Moreover, such a product can also allow you to use higher magnifications and increase the resolution of measured signal. Prolong Gold Antifade Reagent meets these requirements ideally.

The only shortcoming of the Prolong Gold Antifade Reagent is the “Go” part. You really need to go home for a while (or at least away from the slides) to be able to check your results at a microscope. The Prolong Gold Antifade Reagent needs at least 24 hours to polymerize completely. And a risk of muddying fragile microscope optics with un-solidified mounting medium, or destroying the samples by accidentally sliding still-mobile cover-slips against the slides is just too high.

In summary, this is a highly recommended, extremely easy to use, mounting medium for fluorescent applications.