Pathology and Laboratory Medicine

Blotting Techniques

Biochemistry studies molecules such as DNA, RNA and proteins. Blotting techniques are what scientists use to separate these types of molecules. In cells, they exist as a mixture. Blotting allows researchers to find one protein among many, like a needle in a haystack. Blotting is generally done by letting a mixture of DNA, RNA or protein flow through a slab of gel. This gel allows small molecules to move faster than bigger ones. The separated molecules are then pressed against a membrane, which helps move the molecules from the gel onto the membrane. The molecules stick to the membrane, but stay in the same location, apart from each other, as if they were still in the gel.