Patent ID: 7830513

Claim:
A method for interrogating biosensors located within wells of a microplate, said method comprising the steps of: placing said microplate onto a holder; scanning multiple optical beams across multiple rows of the biosensors within said microplate to determine a first position of said microplate and to obtain a first set of interrogation measurements; removing said microplate from said holder; re-inserting said microplate back onto said holder; re-scanning the multiple optical beams across the multiple rows of the biosensors within said microplate to determine a second position of said microplate; determining a position deviation of the microplate by comparing the first position and the second position of said microplate, wherein the position deviation of the microplate is determined by using biosensor displacements (Δx ij , Δy ij ) which are determined from absolute biosensor positions (x ij , y ij ) relative to a single biosensor A 1 measured during the scanning step and the re-scanning step where (i, j) denote (row, column) indices of the wells and by using two equations Δx ij ≈Δθ·(y ij )+ Δx and Δy ij ≈Δθ·(x ij )+ Δy to obtain: a global x-displacement (Δx) value of said microplate; a global y-displacement (Δy) value of said microplate; and a microplate rotation (Δθ) value; calculating a scan trajectory to take into account the position deviation of the microplate; re-scanning the multiple optical beams using the calculated scan trajectory over the multiple rows of the biosensors within said microplate to obtain a second set of interrogation measurements; and comparing the first set of interrogation measurements and the second set of interrogation measurements to determine whether or not a biological substance is present or a biomolecular event occurred on one or more of the biosensors within said microplate.