- A fluid cover medium provides superior morphology and preserves RNA integrity in tissue sections for laser microdissection and pressure catapulting. Micke, P., Bjørnsen, T., Scheidl, S., Strömberg, S., Demoulin, J.B., Ponten, F., Ostman, A., Lindahl, P., Busch, C. J. Pathol. (2004)