In Western blots, proteins are first separated by size, typically in a thin gel sandwiched between two glass plates in SDS-PAGE (described above). The proteins in the gel are then transferred to a PolyVinyliDene Fluoride (PVDF) membrane, nitrocellulose, nylon, or other support membranes. The membrane is probed with antibodies that specifically bind to the protein of interest and are visualized, for example, by fluorescence, chemiluminescence or autoradiography. Enzyme detection is enabled when the antibodies are labeled with an enzyme reporter and the respective chemiluminescent substrate. Western blotting techniques allow not only detections but also quantitative analyses. Analogous protein Slot blot methods to Western blotting are used by MarinBio and others to directly stain specific proteins in live cells or tissue sections.