Inoculation of hybridoma cells into relevant animals to produce ascites. We normally use immuno-sufficient mice to produce ascites. Immuno-deficient mice are available for ascites production for non-murine hybridoma cell lines or murine cell lines of distinct genetic backgrounds. Optimized methods are used to generate tumors and accumulate ascitic fluid. Using nude or SCID mice in ascites production will eliminate the contamination from endogenous mouse IgG.