Patent ID: 7629173

Claim:
A method for detecting and correcting a misalignment of a microplate in an optical reader system, said method comprising the steps of: placing said microplate onto a holder; scanning a fiducial marking on said microplate to determine a first position of said microplate; removing said microplate from said holder; re-inserting said microplate back onto said holder; scanning said fiducial marking on said microplate to determine a second position of said microplate; comparing the first position and the second position of said microplate; and if there is a difference between the two positions, then addressing the lateral and/or angular misalignment of said microplate such that the re-inserted microplate is positioned to be located at or substantially near to the first position, wherein the fiducial marking includes features that are at one angle to a scanning direction of an optical beam and features that are at a second angle to the scanning direction of the optical beam which enables one to determine misalignments if any in two directions.