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Universal amplification system allows ultra-sensitive detection of proteins and microbes

Guanine Inc has announced a revolutionary technology for amplifying protein and microbe detection signals. The platform will enable a new generation of ultra-sensitive tests for the early stage detection of diseases and pathogens.

Guanine’s technology uses microbeads containing millions of oligonucleotides comprising electroactive guanine molecules along with a ligand to bind the microbeads with target analytes. The massive number of guanine tags amplifies the detection signal so each individual analyte can be measured with a low cost electrochemical biosensor. The analytes are captured from a sample using magnetic bead purification to remove nonspecific materials that can interfere with detection. Analytes are sandwiched between magnetic microbeads and amplification microbeads, then guanine tags are eluted to hybridize with complementary cytosine probes on individual biosensor electrodes. A voltammetry scan oxidizes guanine and generates an electrical current proportional to the concentration of the analyte.

When the amplification system was applied to wastewater samples, the technology measured 3 cfu/mL of Escherichia Coli O157:H7 among millions of heterotrophic bacteria and other contaminants, according to a study recently published in the Journal Sensors (Highly Sensitive Bacteria Quantification Using Immunomagnetic Separation and Electrochemical Detection of Guanine-Labeled Secondary Beads).

“The technology is extremely flexible,” said Dr. Bruce Gale, Chief Science Officer of Guanine Inc and Professor at the University of Utah. “Our study team was able to improve detection sensitivity by increasing the number of guanines per microbead. If bacteria are alive, we can use a second test to measure an increased detection signal in a fraction of the time of cell cultures. This can be a boon for rapid antimicrobial susceptibility testing. We are now evaluating different magnetic bead purification protocols to adapt the technology for various types of bodily fluids and environmental samples.”

“Detecting diseases at an early stage provides more treatment options and lower treatment costs,” said Neil Gordon, President of Guanine Inc. “But an ultra-sensitive test can miss the disease if it measures a biomarker that is a poor indicator. Our technology changes the paradigm because for the first time ultra-low levels of proteins, microbes and nucleic acids can be amplified and quantified in the same test. Healthcare professionals can make better treatment decisions using tests that measure a diversity of biomarkers such as specific bacteria strains, and protein toxins produced by the bacteria, and a drug resistant biomarker, and antibodies secreted by the body’s immune system.”

Guanine Inc, in partnership with the University of Utah, offers a custom service for developing rapid, simple and inexpensive tests that apply the amplification technology. “We work with our customers to define test objectives and then develop and validate assays, deliver kits that can be evaluated at customer sites, and prepare assay commercialization paths that can include distribution and/or licensing,” according to Tom Samek, VP of Business Development at Guanine Inc and President of Voligo Inc, an affiliated company for licensing and distribution. “We are actively seeking customers and strategic partners including diagnostics companies, pharmaceuticals, antibody suppliers, and government agencies, along with academic researchers interested in pursuing research grants.”


Highly Sensitive Bacteria Quantification Using Immunomagnetic Separation and Electrochemical Detection of Guanine-Labeled Secondary Beads, Harikrishnan Jayamohan, Bruce K. Gale, Bj Minson, Christopher J. Lambert, Neil Gordon and Himanshu J. Sant, Sensors, doi:10.3390/s150512034, published 22 May 2015.

Source: Guanine Inc