PCR and multiplexing

Genera’s technology is based on its AmpaSand platform, modified silica beads that are coded with reference to size and colour intensity and are designed to be analysed by flow cytometry.

“We can code sub-clusters of beads within a group, and those sub-clusters can be individually identified by a flow cytometer,” Bollands says. “Those sub-clusters also have DNA markers on them that we can use to detect HPV and so forth.

“The key point for us is that the level of multiplexing we achieve is huge. Because we can code with reference for size and colour, the theoretical upper limit of our multiplexing ability is about 150 or 160, not withstanding all of the other variables that go into that.

“The other nice thing about the silica beads is that because they are extremely heat-resistant, we can put in fairly high stringency procedures, and that allows us to do very specific binding procedures.

“We have a particular piece of technology called enhanced solid phase PCR (ESP PCR), which allows us to do the PCR and the hybridisation of the beads in the same vessel. It shortens processing time and reduces the number of handling steps, and you can’t do that with latex beads, because they tend to gloop. That’s the very technical word we use.”

The company has also developed QPlots, a proprietary interpretive software for the interpretation of flow cytometry outputs. The software makes a call on each individual specimen, identifying whether it is high-risk HPV positive or negative, low-risk HPV positive or negative, such as for types 6 and 11, which cause can cause genital warts, or indeterminate. The whole test is carried out in a high-throughput, 96-well format.

“We can pretty much put any DNA marker onto our beads,” Bollands says. “We have some thoughts about how to extend our STD franchise, but I’m also personally quite interested in the pharmacogenetics side of things. We have started to explore some options looking at responsiveness to drugs and propensity of certain drugs to cause side-effects that are related to SNPs.”

Genera is commercialising molecular diagnostic products that sit in a sweet spot for corporate interest, he says. “It all has to be executed but the ideas are right. It is an interesting time and we are in the right space.”