A SIMPLE, RAPID METHOD FOR ISOLATING RNA FROM PARAFFIN-EMBEDDED TISSUES FOR REVERSE TRANSCRIPTION-POLYMERASE CHAIN-REACTION (RT-PCR)

Described here is a simple, rapid technique for isolating RNA from arc hived formalin-fixed, paraffin-embedded tissues (PETs). Using this mod ified acid guanidinium thiocyanate method, RNA sufficient as a templat e for the reverse transcription-polymerase chain reaction (RT-PCR) can be isolated in 2 hr from a single 20-mu m-thick section of tissue. Sp liced mRNA corresponding to portions of the estrogen receptor (ER) gen e was successfully amplified from fixed, embedded human breast cancers containing increased amounts of ER protein. This method makes it feas ible to safely and efficiently isolate RNA from large numbers of routi nely processed paraffin blocks for retrospective studies of endogenous proteins such as hormone receptors, oncogenes, and viruses.