Blotting membranes are thin and porous membranes that are used in molecular biology as part of blotting techniques to transfer and immobilize proteins, DNA, or RNA onto a membrane from a gel. Blotting membranes are typically made of substances such as nitrocellulose or PVDF. These membranes help to retain the biomolecules strongly on them to enable their detection by antibodies or probes. They are commonly used in biotechnology, pharmaceuticals, and research labs.