Abstract: In a method for providing rapid and simple manually driven alignment of image segmentation grids to images of imperfect mircroarrays, an image of a microarray composed of multiple sub-arrays or blocks is displayed and a nominal grid composed of corresponding sub-arrays or blocks is superimposed on that image. Comer markers of a grid block are dragged to coincide with the spots at the corresponding corners of the underlying image block. The locations of the intervening grid markers in that block are automatically adjusted by linear interpolation in two dimensions. The corrections generated for this grid block are then applied automatically to all of the other blocks in the grid. Following this, the corner grid blocks are dragged to align a single corner marker within each corner grid block with an image spot at the corresponding corner block of the image, and all of the intervening grid blocks are automatically aligned to these by linear interpolation in two dimensions.