Methods and assemblies for high throughput screening

A method of screening a plurality of sample fluids for molecules which can bind to predefined ligands, using an assembly comprising, a sample delivery unit which can receive sample fluids to be screened, and a plurality of groups of flow cells, each group having at least two flow cells, each group comprising at least one flow cell which has a test surface having a first type of ligand and another flow cell which serves as a reference flow cell, and a means for selectively fluidly connecting the sample delivery unit to any one of said groups of flow cells, the method comprising the steps of,

• selecting one of said plurality of flow cell groups by fluidly connecting said flow cell group to the sample delivery unit;
• carrying out an injection step which comprises injecting a sample fluid to be screened from the sample delivery unit into the flow cells in the selected flow cell group;
• for each flow cell in the selected flow cell group, recording a signal which is output from a sensor, wherein said signal represents the binding of molecules of the sample fluid to ligands on the test surface of that flow cell and/or the dissociation of molecules from ligands on the test surface of that flow cell;
• carrying out a damage assessment step, using said recorded signals, to determine if the test surface of a flow cell in the selected flow cell group is damaged;
• if it is determined from the damage assessment step that the test surface of a flow cell in the selected flow cell group is damaged, then selecting another one of said plurality of flow cell groups by fluidly connecting said other flow cell group to the sample delivery unit.