LATE-PCR

LATE-PCR (Linear After The Exponential Polymerase Chain Reaction) is a special type of
PCR that offers some unique advantages for identifying  high threat bio agents such as Bacillus anthracis, Yersinia pestis and Franciscella tularensis down to extremely trace quantities. 
LATE-PCR is a novel form of asymmetric PCR, which provides significant technical advantages over symmetric real time PCR and also allows for high quality endpoint analysis.

The following figure illustrates how a LATE-PCR reaction progresses compared to conventional symmetric PCR. LATE-PCR typically utilizes two primers per target, an excess primer and a limiting primer. The concentrations are such that the limiting primer is exhausted during the early stages of exponential amplification, typically around the Ct of a real time reaction.

The key feature for LATE-PCR’s efficiency is that the primer design takes primer concentration into consideration when designing the primers to specific melting temperatures (Tm). Primer concentration directly affects a primer’s functional Tm and must therefore be incorporated into the primer design process. As a result, the LATE-PCR reaction efficiently generates single stranded amplicons after a short period of exponential amplification. This enables one to detect low numbers of target organisms (single digit limits of detection have been demonstrated), perform endpoint analysis, significantly increase the level of multiplexing in an assay, and provides the ability not only to identify, but to differentiate bacteria at the strain level.  

Smiths Detection has an exclusive license for LATE-PCR from Brandeis University for all markets, worldwide and has obtained licenses from Public Health Research Institute and Biosearch Technologies for the Molecular Beacons probe technology and fluor/quencher technologies, respectively.

 

Smiths Detection - LATE PCR