Bio-Rad QX200™ AutoDG™ Droplet Digital™ PCR System - Manual (Page 9)

Instruction Manual | 1 vi | Automated Droplet Generator vi | Automated Droplet Generator
QX200
™
AutoDG
™
Droplet
Digital
™
PCR System
1
1.1 Introduction
Bio-Rad’s QX200 AutoDG Droplet Digital PCR (ddPCR ™ ) system combines
water-oil emulsion droplet technology with microfluidics to perform accurate and
precise digital PCR. The system consists of two instruments — an Automated
Droplet Generator and a Droplet Reader — and associated consumables. The
Automated Droplet Generator partitions each sample into ~20,000 uniform
nanoliter-sized droplets in which nucleic acid molecules are distributed in a
random fashion. Each droplet serves to partition the reactions. The 96-well PCR
plate of droplets is removed from the AutoDG Instrument, sealed, and PCR
is performed to end point in a thermal cycler. Droplets from each sample are
analyzed individually on the QX200 Droplet Reader; the droplets stream single
file through the reader for fluorescence analysis.
PCR-positive and PCR-negative droplets are counted to provide absolute
quantification of target DNA in digital form. Positive droplets, which contain
at least one copy of the target DNA or RNA molecule, exhibit increased
fluorescence compared to negative droplets. The fraction of PCR-positive
droplets enables the target to be quantified according to the Poisson
distribution. Alternatively, amplified products can be extracted from droplets
following PCR for downstream applications, such as sequencing or cloning.
The QX200 System works with both hydrolysis probes and EvaGreen
fluorescence detection chemistries, and its flexible design allows for high
throughput and ultra-sensitive detection.