TECHNOLOGY

Real-time PCR assays are not truly quantitative because they require
assumptions of unbiased and  equivalent amplification efficiency of each
nucleic acid molecule in different samples.  In dilute sample preparations,
the number of template molecules can be counted by subdividing the
sample into many drops prior to PCR.  Simply counting the number of
drops with amplicons provides a near absolute count of the number of
template molecules in the solution of interest.    


    Digital PCR and nucleic acids counting.  Nanoplates and
    DigitalDrops can be used for absolute quantization of nucleic
    acids.  The nucleic acids sample is diluted and mixed with qPCR
    Master Mix. The PCR ready sample is then subdivided into droplets
    and thermal cycled for 30 rounds. In the signal image at cycle 30,
    bright spots indicate the presence of target and the no target
    sequence regions remain dark.  A bright spot can contain more
    than one target sequence.  However, the probability of a spot
    containing more than one nucleic acid molecule decreases when
    less than 50% of the drops form bright spots.