deltaDOT's Peregrine preys on mass spec applications

The instrument combines a novel UV analysis method - Label Free Intrinsic Imaging (LFII) - and advanced software analysis tools with capillary electrophoresis (CE) separation technology to allow the label-free analysis of proteins, DNA and RNA fragments, small molecules, bacteria and viruses. The first batch of instruments have already found homes in leading UK and US pharmaceutical and biotechnology companies as well as in academic research institutions. "The technology is application agnostic,"​ said Richard Lingard, deltaDOT's vice president of sales. He continued by explaining that the instruments could be used for numerous applications, including proteomics and biological research, biological drug production quality assurance (QA) / quality control (QC) and even forensics. The company have shown that the technology in the Peregrine can complete analysis of an Escherichia coli (E.coli)​ lysate in 18 minutes and can analyse antibodies as well as separating and quantifying the ratio of enantiomers from racemic mixtures by adding highly sulphated cyclodextrins to the run buffer. They have also demonstrated the system's ability to perform viral titre analysis on Baculovirus expression systems. ​Peregrine can also be used to investigate protein-ligand interactions by studying the difference in migration time between complexed and non-complexed proteins, analogous to a band shift in CE. Dr Stuart Hassard, deltaDOT's co-founder and head biologist, explained that because the instrument can detect any molecule that absorbs in the UV, it could be used in a plethora of applications which involve the analysis of any molecule that contains a double bond or aromatic ring - encompassing virtually all biological molecules and small-molecule drugs. "A lot of people use mass spectrometry to do QA/QC and there are some applications of mass spec like this that we are targeting, especially as our instrument costs a fraction of the cost of a mass spectrometer to buy and run,"​ he said. The instrument has a relatively small footprint and the only moving parts are in the autosampler apparatus, making the instrument very robust and amenable to movement. The company was founded in 2000 by Dr Stuart Hassard, deltaDOT's head of biology, and his brother, Dr John Hassard, deltaDOT's chief technology officer and a reader in the Department of High Energy Physics at Imperial College in London. deltaDOT is currently investigating the incorporation of microfluidics into the next generation of the instrument which would not only shrink the instrument further, but also make it even more robust. Dr Stuart Hassard told LabTechnologist that he believes that: "this will be the big quantum leap for microfluidics," ​ The core concept of the technology was conceived by the brothers after a family Christmas lunch in 1995. The system is designed around a detector system that contains 512 pixels along the length of a capillary window that takes data readings of molecules flowing through the window at up to 60 times a second (60 Hz). This leads to tens of thousands of data points being generated a second and is where the know-how of a particle physicist comes into play, as they are used to analysing such vast quantities of data. The data generated is then analysed in three distinct steps using the company's Equiphase Vertexing Algorithm (EVA). The first step identifies the peaks and generates an 'equiphase map' of peak time and height that tracks the movement of the separated molecules across the window to give. The next step takes the map and determines the vertex point at which the tracks converge with molecules from the same injection meeting at the same vertex. This vertexing allows the identification of separated components from multiple injections. "If the data track doesn't meet the vertex then the software just throws that data away reducing background noise,"​ said Dr Hassard. This feature is particularly useful in DNA sequencing applications where four dideoxynucleotide reactions are injected individually before data analysis allows base calling. The final step of the analysis produces a graph in which the individual molecules are represented by sharp peaks that indicate their molecular weight and shape with a signal-to-noise ratio 10 times that of a single electropherogram. The company claims that the results are far superior to both conventional polyacrylamide gel electrophoresis (PAGE) and conventional CE methods giving quantification to an accuracy of within 1 or 2 per cent relative standard deviation (RSD) and reproducibility within 1 per cent error. This highly sophisticated approach allows the separation and detection of small peptides with a charge based resolution of 1 Dalton (or atomic mass unit). This high level of accuracy allows the identification of post-translational protein modifications such as glycosylation and phosphorylation. The company's other instrument, Merlin, can sequence 200 base pairs in less than 3 hours including the PCR sequencing and sample preparation, as well as analyse Short Tandem Repeats (STRs). This instrument uses similar technology, but with a different pressure injection setup to accommodate the higher viscosity sequencing matrices and specific software to allow sequence analysis. The Peltier temperature control maintains the temperature of the instrument to within 0.1º over a 24-hour period which is very important for sequencing applications. deltaDOT is currently looking for partners to finish the industrialisation of the product. The company has developed various applications for the technology with a variety of customers, including a collaboration with Proctor & Gamble that helped develop the proteomics applications. "We are always looking for partners that can use our technology to enhance what they are doing,"​ said Dr Hassard. "We are currently very involved with two major collaborations but always have space to talk to more,"​ he added. deltaDOT is also working on a biomolecular stability platform known as Osprey to look at protein folding applications.