Wnt 3a conditional medium - (Mar/11/2009 )

I am planning to use Wnt 3a protein in my organotypic tissue culture (embryonic Kidney). There were studies using Wnt 3a conditional medium which is produced by L cells. I also found Wnt 3a recombinant protein produced by R&D systems. Which one is good? What are the pros and cons?

The pros and cons are many:

Conditioned medium Pros: is easy to produce, cheap and you have a continuous supply. However (Cons), it is also a pain to prepare - you have to add medium to the L cells, remove it after 24 hours, filter and store it appropriately, but not for too long as many of the things being produced will decay quite quickly. It is essential that you remove all the L cells so as to not contaminate your other cultures (a big problem if you do) and that it is bacteria and fungus free. You have to make sure that the medium you are using isn't depleted of other nutrients by the conditioning process as this will affect the growth of your main cultures. Conditioned media also contain a whole heap of excreted products from the feeder cells (L cells) which may or may not be good for your other cells, and how will you tell the effects of these from the wnt 3 effects if that is what you are studying.

recombinant protein: Pros: purity, single component system (i.e. no other things being added). Cons: Cost?, avaliability?, preparation (what does it dissolve in?, how will this affect your cells?).

I am sure there are more to each side of the argument, but I have to get back to work.