Development in a primary cell culture of the marine sponge Ircinia muscarum and analysis of the polar compounds

We have established a primary cell culture of the marine demosponge Ircinia muscarum. The culture was started from a cell suspension obtained by a com bination of mechanical chemical means. Microbial contamination was controll ed by the use of a pool of antibiotics. Optical density, rather than hemocy tometer count, is suggested to monitor the cellular growth.;Analysis of the chemical composition of I. muscarum cells revealed absence of sterols, sho wing that the cells were unable to biosynthesize sterols. When the medium w as supplemented with cholesterol an increase of about 70% in the number of cells was observed. These results suggest that the classic mammalian nutrie nt medium was not satisfactory for I. muscarum cell growth, and sterols wer e needed to satisfy the membrane requirements.