Operation and performance of an automatic metaphase finder based on the MRC fast interval processor

The Medical Research Council's fast interval processor (FIP) has been adapted for metaphase finding and selection. This article summarizes recent improvements to the hardware, and describes the selection of image features. The system uses a highly simplified but effective clustering procedure to reduce computation time, and incorporates a ranking algorithm based on computed cluster features so that high-quality metaphases can be preferentially selected. Experimental results indicate that the system can detect high-quality metaphases rapidly in "rich" material and a high proportion of the available metaphases in "sparse" material. It can handle a wide range of material with good repeatability of performance.