adminImmunoassay tests are commonly used to diagnose a whole host of disease medical conditions. In general the technology behind them relies on the manipulation of paramagnetic assay beads as analyte labels, as they are easy to manipulate magnetically, moving them through the assay process and concentrating them in a detection area. These beads have the unique property of being super-paramagnetic; they are only magnetic when placed in a very strong magnetic field (bias field), which is critical to their success as labels for analyte detection. These analytes/assay beads are usually captured and immobilised in a line, typically on a nitrocellulose strip or on a microfluidic strip deposition area.
Conventional assays detect and measure these analytes on their capture line or trap areas using optical instruments to measure reflectance, contrast, colour change or fluorescence emitted from the nanoparticle coating. However, a great deal of these analytes are not detected by the optical measuring device, resulting in poor accuracy, especially in POC devices where optical instrument quality is limited by cost and/or size.
While other devices are limited to imperfect optical detection, MIDS detects magnetically to a whole new level of accuracy: The MIDS patented technology utilises miniaturised highly sensitive custom built “Hall Effect” magnetic sensors embedded within a test strip as a Lab-On-Chip device. Hall Effect sensors are commonplace; to be found in virtually every electronic device Hall Effect sensors are commonplace; to be found in virtually every electronic device from an alarm clock to a zip drive. They sense low levels of magnetic signature from magnetic device components. Immunoassay beads are
The highest performing cardiac biomarker POC devices have a coefficient of variance in the 10% range at the 99th percentile (CV), although in reality they are unable to detect very low biomarker levels. By example, the POC device claiming to be the only one which conforms to tightened FDA guidance claims the device only achieves this CV at a detection of 36 ng /L. We believe our ability to measure the aggregated nano-Tesla paramagnetic signature of the particles themselves, when applied for example to HS cTn assays, will achieve > 5% CV on assays down to 2 ng cTn /l. Accuracy on this level matches state of the art central laboratory analyzers.
Our measurement technique should also require very low volumes of fluid sample, typically less than 5 μL (one small drop) for a single biomarker test using a finger stick blood sample on a microfluidic test strip for cTn- an industry leading low volume. This untreated finger stick sample innovation is material: competitor POC devices require, as a minimum, several times this whole blood volume. Blood volumes required by competitors are typically 100 – 200 µl, and can be as high as 2 ml (2000 µl). Many competitor blood samples also require pre-treatment (Heparain, EDTA). Our ability to use a very small & untreated sample allows us to contain an assay on a single
NanoTesla Dx world class team is developing POC hand held devices using a next-generation nano magnetic medical diagnostic technology.
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