Injection of human cell culture conditioned media into nude mice - (Jan/21/2013 )

Hi all. I've been trying to find a protocol online with injection of conditioned media. I making conditioned media using primary human tissue and I'd like to co-inject cancer cells with conditioned media i.p. into nude mice. Does anyone know whether the conditioned media would have an adverse effect in the nude mice? I've heard about b-cell reactions against conditioned media in nude mice and was told to use SCID mice, but I'd like to avoid that. I suspect that it won't make a huge difference, but was hoping I could get a more certain answer. Thanks (references are welcome!)

maybe you would need a control too. I mean a nude mice injected with conditioned media only, and then compare with the co-injected one?