Technology Description: The invention is an improved way to synthetically produce circular RNAs, which can be used as molecular markers to detect and identify pathogenic RNAs associated with certain plant and animal diseases. Circular RNAs can be synthesized by inserting DNA fragments into a plasmid containing sequences for spontaneous cleavage and self circularization. The invention is a more efficient and consistent process because it takes advantage of sequences in the plasmid that perform this step naturally. The invention also involves a method using a two-dimensional polyacrylamide gel electrophoresis system that separates, analyzes and determines the precise sizing of linear and circular RNAs produced under the synthetic method. Synthetic production of circular RNAs has been attempted in the past, but those methods require extensive purification. Likewise, prior electrophoresis systems require a laborious calibration of gels. Under the invention the size of the RNA is determined by the size of the DNA inserted into the sequence, so markers of varying sizes can be produced. Reference: Please refer to Patent Number 6,210,931, "Ribozyme - Mediated Synthesis of Circular RNAs," which issued on April 3, 2001. Inventors: Robert A. Owens Henry A. Wallace Beltsville Agricultural Research Center Molecular Plant Pathology Laboratory Beltsville, Maryland 20705 (301) 504-6209 / Fax: (301) 504-5449 rowens@asrr.arsusda.gov Laurene Levy (Formerly with ARS) John W. Randles Department of Crop Protection University of Adelaide-S. Australia Glen Osmond Paul A. Feldstein CEPRAP, University of California Davis, CA 95616  (919) 757-3036 / Fax: (919) 753-2697