i am planing a study where i am going to inject a hydrocarbon oil in peritoneal cavity of mice which would lead to formation of ascitic fluid afetr 3 months. I have to investigate certain cytokines in the ascitic fluid. For control group i am injecting saline in place of oil. but no ascitic fluid formation takes place in this group. I want to ask do i really need a control group in this kind of study? or should i just flush the cavity of both control and test group with 1ml of PBS and investigate the parameters in both groups? please help...
thank you














