Rolling circle amplification (RCA) has been useful for detecting point mutations in isolated nucleic acids, but its application in cytological preparations has been problematic. By pretreating cells with a combination of restriction enzymes and exonucleases, we demonstrate RCA in solution and in situ to detect gene copy number and single base mutations. It can also detect and quantify transcribed RNA in individual cells, making it a versatile tool for cell-based assays.
The United States Government has rights in this invention pursuant to contract No. W-7405-ENG-48 between the U.S. Department of Energy and the University of California, for the operation of Lawrence Livermore National Laboratory; NIH grant CA55861 and DOE Grant KP110202.