Liquid handling means for performing assays using plate-like liquid contacting means with force controlling element

An apparatus for conducting assays on samples and/or processing of samples, said apparatus comprising:

• a cylindrical sample holder for holding a sample at a lateral surface of the cylindrical sample holder, wherein said cylindrical sample holder is rotatably arranged;
• wherein said cylindrical sample holder is configured to be at least partly covered by a liquid layer;
• a liquid dispensing means configured to add liquid to the liquid layer, wherein the liquid dispensing means is connected to a first container for holding the liquid;
• a reagent dispensing means configured to add a reagent to the liquid layer, wherein the reagent dispensing means is connected to a second container for holding the reagent;
• and
• a liquid contacting means configured to distribute liquid within said liquid layer, wherein said liquid contacting means comprises a plate-like element having a substantially flat surface adapted to contact the liquid layer, the plate-like element being flexibly assembled in relation to the cylindrical sample holder, such that the plate-like element can be arranged at a first predetermined distance from the cylindrical sample holder when no external forces are acting on the plate-like element, and at a second, larger distance from the cylindrical sample holder when the liquid layer is exerting a force on the plate-like element upon rotation of the cylindrical sample holder, wherein the plate-like element is attached to a force controlling element configured to control an amount of force that the plate-like element exerts on the liquid layer, wherein the force controlling element comprises a flexible portion configured to be contracted upon application of a force from the liquid layer upon rotation of the cylindrical sample holder, thereby increasing the distance between the plate-like element and the cylindrical sample holder as long as the force is applied.