DNA microarray inspection by interference microscopy

DNA microarrays are important new objects for biologists, offering new methods for high speed genetic studies. Many of them are manufactured by depositing small spots, containing DNA molecules, on a coated glass slide. The quality of the spots (homogeneity, shape) is an important factor in the quality of the analysis. We have built a Linnik-type interference microscope providing three-dimensional (3D) topographic images of surfaces with a sensitivity of a few tens of picometers in height. This microscope has been applied to obtain 3D images of DNA microarray spots. We demonstrate the ability of the system to reveal the quality of DNA spots. (C) 2001 American Institute of Physics.