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Matthews Annotated Patent Digest, Section 20:17. Pure or synthetic forms of naturally occurring compositions. This section describes the changes in the court's position over time regarding the patentability of isolated DNA molecules. Prior to the Supreme Court's decision in Myriad, the Federal Circuit ruled that natural DNA isolated from the body was sufficiently different than DNA as it is found in the body because chemical bonds are cleaved to excise it from the chromosome. The Supreme Court reversed this ruling in part, stating that natural isolated DNA was not patentable, but synthetic complementary DNA (cDNA) was patent eligible because introns in the natural DNA are spliced out of the DNA in the process of synthesizing cDNA from messenger RNA in the laboratory.**