Orcein (Orcein, archil, orchil, lacmus, litmus, orcein, orsin, litmus, E182) - matema matema makristasi. Ivo vanoshandura ruvara kuva rutsvuku munzvimbo ine acidic uye bhuruu mune alkaline imwe. Kemikari fomula C28H24N2O7.
Iyo yekuwedzera haina kubviswa pane iyo rondedzero ye "Chikafu chinowedzera chekugadzira chikafu" kune iyo Sanitary uye Epidemiological Mitemo uye Mitemo (SanPiN 2.3.2.2364-08) muna 2008.