Slow galactose induction

Hi,

I am looking for suggestions as to why my galactose induction process
takes 6 hours. I am expressing CFP under a gal promoter in media with
no glucose and 2% galactose. I am getting fluorescence, but it takes
6 hours to see it. Any ideas why induction could be taking so long?

I grow the cells up in media containing no glucose (2%raffinose)
overnight. Then I induce 150uL of this culture with 2% galactose and
measure fluorescence every 15 minutes. I do not see fluorescence
distinguishable from background until about 6 hours later.

Thanks very much for any suggestions! Please reply to [Only registered users see links. ].
Thanks,
Kerry