From: Yue, Y., Behra, R., Sigg, L., & Schirmer, K. (2016). Silver nanoparticles inhibit fish gill cell proliferation in protein-free culture medium. Nanotoxicology, 10(8), 1075-1083.

This study focused on the establishment of a new RTgill-W1 cell strain able to proliferate in a serum- and protein-free culture medium. The resulting RTgill-W1-pf cell line allowed for the first time to study a long-term nanoparticles effect in an in vitro cell culture system without interference by serum proteins or other, undefined serum constituents.

RTgill-W1-pf cells resulted from adaptation to the protein free culture medium, InVitrus VP-6 medium. The exact composition of the InVitrus VP-6 medium is not available from the company but it is clearly protein-free as also demonstrated from the protein measurements performed here. Compared to L-15 medium for wild type RTgill-W1 cells, the InVitrus VP-6 medium contains much more metabolic precursors than the L-15. For example, InVitrus VP-6 contains trace elements such as Fe, Cu and Zn and lipid precursors (fatty acids), such as linoleic acid. The major C-source in InVitrus VP-6 is glucose, not galactose/pyruvate as in L-15. InVitrus VP-6 is buffered with sodium hydrogen carbonate while the L-15 is buffered with phosphates (http://www.cellculture.com). RTgill-W1-pf cells divide in InVitrus VP-6 medium with a doubling time (6 days) similar to the original RTgill-W1 cells (7 days) grown in L-15 medium supplemented with 5% FBS.