The purpose of this research is to study a new way to test for chromosome abnormalities. Chromosomes are strands of DNA (the genetic material in the cell nucleus) that are made up of genes-the units of heredity. Chromosome abnormalities are usually investigated by staining the chromosomes with a dye (Giemsa stain) and examining them under a microscope. This method can detect many duplications and deletions of pieces of chromosomes and is very accurate in diagnosing certain abnormalities. It is not useful, however, for identifying very small abnormalities. This study will evaluate the accuracy of a test method using 24 different dyes for finding small chromosome abnormalities.