Can you probe with less than 18.75 ug of cRNA?
The Core has conducted hybridizations with as low as 2.5 ug of cRNA with some systematic deviations as compared to 18.75 ug of cRNA. We recommend 18.75 ug; it is your decision. If you decide to use lower or higher amounts you should keep that consistent among all of your experiments if you plan on comparing chips from different experiments.