beta gal expression

[Patrick Van]

     Dear,

     Can anyone give me his (her) experience with measuring expression of
     beta galactosidase acivity in yeast cells growing in liquid cultures.
     Can one detect the blue color (from the Xgal) in a photometer or thus
     this only appear when growing on the plate.
     References are also very welcome

     Patrick Van Dijck
     Janssen Research Foundation
     department of biochemistry
     fax: (32)14605403
     email: pvdijck at janbe.jnj.com