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The inqaba biotec GS-FLX platform is Africa’s first high-speed, complete solution, and efficient high-throughput sequencing service. This BioPad funded initiative is aimed at assisting all scientists, both locally and internationally.  The Genome Sequencer system was developed using novel 454 technology. It allows life scientists to enjoy the benefits of fast, accurate, and cost-effective high-throughput sequencing. This versatile technology enables the sequencing of many sample types, including short DNA fragments, amplicons, shotgun fragments and paired ends.
Dr Arshad Ismail, the GS Technology Platform Manager, and the inqaba biotec GS Facility inqaba biotec is a professional and experienced team and has generated over ~3.0 GB of data since March 2007. During this time, the GS technology has been improved from an initial 20 MB per run (~100 base read length) to the 100 MB per run of the GS FLX (~250 base read length) and now the 500 MB per run of the GS Titanium (~500 base read length). Evolution of the 454 sequencing increasing reads/run, read length and throughput
1. Flexibility:
2. Speed:
3. Accuracy:
4. Productivity:
5. Cost Efficiency
6. Easy to use
How does GS FLX/Titanium Technology work?
Our GS FLX/Titanium sequencing platform supports sequencing from a wide variety of sample types. These include: genomic DNA, PCR products, BACs and cDNA. 5 - 10 µg of gDNA samples are nebulized into small 500 to 800 base pair fragments, using high pressure Nitrogen gas. The smaller samples, such as small non-coding RNA (siRNA) and PCR amplicons, do not require this step.  Fragmentation of the gDNA using Nitrogen Nebulisation
Short specific adaptors (A and B) are ligated onto each small fragment. These are vital for the steps that follow, including purification as the B adaptor as an attached biotin label. The dsDNA fragments are purified using Streptavidin beads.  dsDNA with ligated adaptors
Purification of the dsDNA with ligated adaptors using Streptavidin beads
 The water-in-oil emulsion showing the microreactors The emulsion is aliquoted into PCR plates for amplification. Clonal amplification of microreactors occurs simultaneously, and each bead ends up with ~106 clonal copies of the sstDNA.  A clonally amplified bead with ~106 copies of the sstDNA
The GS FLX Titanium PicoTitrePlate™ has been modified and now has a metal coating that prevents cross talk between the wells. There are approximately 3.4 million wells per plate and each have a diameter of 29 µM. This ensures that only 1 bead (diameter of 20 µM) is able to fit into each well.
The GS Titanium PicoTitrePlate™ The clonally amplified sstDNA beads are added to the DNA Bead incubation Mix which contains DNA polymerase. This is layered with Enzyme beads (containing sulfurylase and luciferase) onto the PicoTitrePlate™ device. The loaded device is centrifuged and the beads are deposited into the wells.
Loading of the PicoTitrePlate™ Once loaded, the PicoTitrePlate device is placed in the GS instrument against a powerful CCD array. Loading the PicoTitrePlate™ into the GS instrument Sequencing reagents (containing buffers and nucleotides) are flowed across the wells of the plate by the fluidics sub-system. Separate nucleotides are flowed across the plate in a fixed order, allowing each of the thousands of beads with millions of copies of DNA to be sequenced in parallel. As a nucleotide complementary to the template strand is added, the DNA polymerase incorporates it into the growing DNA strand. This results in a light reaction and is recorded by the CCD camera in the instrument. The intensity of the light signal is directly proportional to the number of nucleotides (i.e. homopolymer stretches) that are incorporated in a single flow.
The sequencing by synthesis reaction
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454 GS FLX Sequencing