Thermo Scientific™ Nunc™ Nunclon™ Delta cell culture products are tested for cell growth and plating efficiency using several different cell lines. Nunc Nunclon Delta products are tested with two cell lines L929, HEL 299 or F2002 and one Primary Chick Embryo cell culture for monolayer formation, plus cell line V79-4 for cloning efficiency. The HEL 299 cell line is derived from embryonic lung tissue of a human male. It is a diploid fibroblast-like cell line initially developed for use in vaccine development. This Tech Note describes a procedure for culturing HEL 299 cell line on a Nunclon Delta treated surface.