Polony: A tiny colony of DNA, about one micron in diameter. The word "polony" is a contraction of "polymerase colony." To create polonies, a solution containing dispersed DNA fragments is poured onto a microscope slide. An enzyme called DNA polymerase is added. It causes each fragment to copy itself repeatedly, creating millions of polonies, each dot containing only copies of the original fragment of DNA. The polonies are then exposed to a series of chemically-labeled DNA base probes that are fluorescent and light up when run through a scanning machine, identifying each nucleotide base in the DNA fragment. In addition to its application to DNA sequencing, polony technology can be used to study the transcriptome (RNA content) of cells and to determine differences in genome sequence between different individuals.