chemotactic

This term is used almost exclusively within scientific and medical registers, specifically in biochemistry, immunology, and microbiology. It describes a precise biological mechanism where cells move in a directed manner toward or away from a chemical gradient, such as a white blood cell migrating toward a bacterial toxin.

Because it is a technical descriptor, it is rarely used in casual conversation. It is most frequently paired with nouns like response, factor, or gradient to specify the nature of the cellular attraction or repulsion.