Yield and quality of RNA and DNA extracted simultaneously from needle core biopsies. Nucleic acids were extracted from samples processed according to protocols B and E. (a) Quantity of RNA extracted represented as mean yield of RNA. (b) Integrity of RNA represented by RNA integrity number. (c) Quantity of DNA represented as mean yield of DNA. Error bars in panels a–c represent the standard error of the mean (s.e.m.), with a minimum of six biopsies used for each protocol. (d) Integrity of DNA as verified by agarose gel electrophoreses. A 1-kb DNA ladder was run as a marker in each gel.