Allelic exchange inFrancisella tularensisusing PCR products

Allelic exchange in Francisella tularensis using PCR products.

We describe here a technique for allelic exchange in Francisella tularensis subsp. novicida utilizing polymerase chain reaction (PCR) products. Linear PCR fragments containing gene deletions with an erythromycin resistance cassette insertion were transformed into F. tularensis. The subsequent ErmR progeny were found to have undergone allelic exchange at the correct location in the genome; the m...

Directional cloning of PCR products.

INTRODUCTION This protocol is for directional blunt-end cloning of DNA fragments. The target DNA is PCR-amplified, 3'-extensions are polished with Pfu DNA polymerase, and the amplicon is ligated to a blunt-ended plasmid DNA. The products of the ligation reaction are used to transform competent Escherichia coli. A restriction enzyme is added to the ligation reaction (Liu and Schwartz 1992) to re...

Purification and Concentration of PCR Products Leads to Increased Signal intensities with Fewer Allelic Drop-Outs and Artifacts

Capillary electrophoresis of amplified DNA isolated from trace evidence samples occasionally results in inadequate STR-profiles due to artifacts caused by, e.g. primers and dNTPs. Removal of artifacts by purification and subsequent concentration of the PCR products may increase the sensitivity and the quality of the DNA profiles without re-amplification of the sample. We have validated and impl...

Gel Purification of PCR Products. Fatemeh Mehrpooyan*

Bandstab: a PCR-based alternative to cloning PCR products.

In many DNA amplification reactions, extra fragments arising from nonspecific mispriming, a mixture of target templates or allelic variation may be generated in addition to the desired product. Some nonspecific bands can be reduced by more stringent annealing conditions, but in cases of allelic variation or other mixed targets, the amplification products may be of the same length but differ by ...