Regocel™ Supplement for NSO Cells (RS-NSO™) 5000X CONCENTRATE RS-NSO™ is intended for use with NSO myeloma cells growing in small, mid-size or large-scale cultures grown under agitated or non-agitated conditions. Here we provide the protocol for 125 ml shake flasks which can represent mid-large scale cultures. Adapt as necessary for static culture in T-flasks or culture plates/dishes. A variety of media (defined, animal-free, and serum-free) can be used with RS-NSO™. Use your preferred commercial or in-house NSO medium. NSO cells to be seeded should be healthy and in log phase growth. Cells would typically express and secrete the product of heterologously expressed gene(s), such as an immunoglobulin, into the medium. Methods to quantify protein such as ELISA should be established in-house. In many cases, commercial ELISA kits are available to measure protein.