The present invention relates to a method, an analyzer and a computer program product for focus prediction in a sample arranged on a measuring surface of an analyzer. The method comprises row wise scanning sample positions by means of an optical system of said analyzer, said sample positions being positions in a coordinate system for said measuring surface containing said sample, for the first sample position on each row, determining a focus and storing said focus, and for each subsequent sample position: if a stored difference exists, predicting a focus by adding said stored difference to said stored focus, or if no stored difference exists, determining a focus and storing said focus.