Soft agar assay - need help/advice!! (Aug/25/2004 )

Hi

I am trying to set up soft agar assays to test a possible functional interaction between an oncogene and another protein i am looking at.

after a few attempts in which everytime the plates became infected (usually with fungus) very quickly after plating the cells...i seem to have eliminated the infection problem (although any other useful tips regarding keeping the plates sterile is welcome)....but now the plates, rather than being a nice pink media colour, have gone yellow after just a day or two...

so in short...

does this yellow colour (presumably due to the plates being the wrong pH) affect the expt?
can you feed the plates by adding new media on top of the agar?
how else can infection be reduced?

grateful for advice on any of these issues

many thanks
Katherine

After your seeding cells mixed with agrose, you can put the plate at 4 C for 1 hour to make the gel ready, then move to the incubator. The fresh medium can be added to the top of the gel the next day.