IPA: //prɪˌsɪpɪˈtɪnədʒən//
KK: /prɪˌsɪpɪˈtɪnədʒən/
A substance that causes the body to produce a specific type of antibody, known as a precipitin, which helps in the immune response.
The scientist studied the effects of the precipitinogen on the immune system.
Precipitinogen is formed from "prae-" (meaning before) and "capere" (meaning to seize or take) combined with "-in" (a suffix used in biochemistry to denote substances). The word refers to a substance that can cause precipitation, particularly in the context of antibodies and antigens.
Think of a substance that 'seizes' or 'takes' something 'before' it precipitates — that's what precipitinogen does.