[49] Tissue-print hybridization for detecting RNA directly

Tissue printing is a simple method for detecting macromolecules blotted directly from the surfaces of severed organs onto nylon or nitrocellulose membranes. The blotting procedure produces an image of the cut surface of the tissues on the membrane, and macromolecules, such as proteins, complex carbohydrates, and nucleic acids, are fixed to the membrane. The retention of nucleic acids on the membrane allows the detection of RNAs by hybridization with either DNA or antisense RNA probes. Tissue-print hybridization is much less time consuming and less expensive than in situ hybridization and requires a minimal amount of technical expertise and equipment. It also has the advantage that numerous tissue treatments or manipulations can be examined with a minimal amount of effort. For example, all of the tissue sections can be printed on a single piece of nylon membrane, and once the tissue prints have been made for each treatment or manipulation, staining, prehybridization, hybridization, and autoradiography can be uniformly carried out on that single nylon membrane.