Specific and sensitive amplification of major outer membrane protein (MOMP) gene (ompA) DNA sequences of Chlamydia species with various MOMP genotypes was achieved by a two-step polymerase chain reaction (PCR). Degenerate, inosine-containing oligonucleotide primers homologous to the 5' and 3' ends of the translated regions of all chlamydial MOMP genes were used in a PCR to amplify a DNA fragmen...

Processed pseudogenes of residual contaminating genomic DNA interfere with a sensitive detection of cytokeratin 18 (CK18) mRNA by reverse transcription and polymerase chain reaction (RT-PCR). This may cause false-positive results when CK18 mRNA is used as a marker for ectopic tumor cells in specimens from cancer patients. To establish a sensitive CK18 RT-PCR by excluding the amplification of pr...

ES cells. This phenomenon has been observed in our laboratory in a number of cases. Clones putatively identified as homologous recombinants by Southern analysis can be quickly checked for random insertion of extra copies of the targeting vector by PCR. Given the small difference in size between the two alleles and use of only two primers common to both WT and mutant DNA, the amplification rate ...