Overlay cell culture medium with oil against evaporation - which oil? (Oct/25/2006 )

I want to use an immersion objective which means to submerge the objective into the culture medium (NOT to confuse with an immersion oil-objective); we like to analyze middle-term time-lapses; as the culture plate is without a cover, and evaporation works, we like to overlay the medium with oil.

Can someone recommend which oil to use? I think a light mineral oil will do such as it was used in early days of pcr, or in IEF; but may be someone has a better idea...

We use light mineral oil for oocyte culture, it's also often used for embryo culture. Several companies sell a specific mineral oil for cell culture use.