ProLong Gold Antifade is specifically designed to help protect fluorescent dyes (i.e. Alexa Fluor) from fading but is not recommended with fluorescent proteins (GFP, RFP, mCherry). It comes ready-to-use and stored at room temperature—just apply a drop on the sample, add a coverslip, cure, and image. ProLong Gold Antifade Mountant is a hard-setting liquid mountant applied directly to fluorescently labeled cell or tissue samples on microscope slides. ProLong Gold delivers optimal protection without significantly quenching the initial fluorescence signal to protect fluorescent dyes from fading (photobleaching) during fluorescence microscopy experiments. It is a curing mounting media with a refractive index (RI) of 1.47 that allows longer-term storage of mounted samples. ProLong Gold Antifade Mountant is offered in a ready-to-use 2 mL dropper bottle, or 10 mL bottle and is stored at room temperature. Just apply a drop on the sample, add a coverslip, cure, and image.

Achieve Excellent Refractive Index Matching Without Acrylic Resins
For high-resolution imaging applications, refractive index matching is critical. ProLong Gold Antifade Mountant will cure to an RI of 1.47 and allows you to avoid using traditional acrylic resins (i.e., fingernail polish), which can damage microscope objectives if they make contact. The refractive index determines how much the path of light is bent, or refracted, when entering a material. In microscopy, refractive index differences between specimen and mounting medium should be minimized and can therefore be reduced by using mountants with a higher RI. Optimizing the RI of your experiment will increase the resolution to provide better quality images. Depending on your sample type, thickness, imaging depth and/or staining reagents (e.g. fluorescent proteins or dyes) and whether you need a curing or non-curing mountant, choosing the right mounting media will impact image resolution and should be strongly considered for optimal experimental design.

ProLong Gold Antifade Mountant is not recommended for mounting samples containing fluorescent proteins such as GFP or TagRFP. For superior antifade protection of fluorescent proteins and fluorescent dyes, ProLong Diamond or ProLong Glass Antifade Mountants are recommended. Please note that ProLong Glass mounting media is recommended for samples > 10 microns and all immersion oil imaging applications. For immediate viewing of a sample, choose our non-curing mountant, SlowFade Gold Antifade Mountant.