Mounting Media Applications
Mounting media holds the sample in place during imaging, prevent the sample from drying out or becoming photobleached, and maintain and preserve the sample for short or long-term storage. Mounting media can also change the refractive index of the space between the objective and the glass coverslip so that it is more closely matched to the refractive index of the glass coverslip itself, providing a better image. The two main types of mounting media are broadly classified as water or solvent-based.
The most common type of water-based media is buffered saline solutions, such as PBS. The use of water-based media requires few post-processing steps after antibody labeling and staining, enabling rapid sample imaging. If you choose a water-based mounting medium, you may also decide to use a sealant, e.g. melted paraffin wax, to create a moisture barrier and facilitate adhesion of the coverslip to the slide.
Unlike water-based mounting media, solvent-based media require samples to be dehydrated before being transferred to the mounting medium. Despite these additional steps, solvent-based media can preserve samples for the longest. The most appropriate choice of mounting media depends on the sample type to be analyzed and the technique of imaging utilized.