Optical Immunoassay for Snake bite Diagnosis

Snake BitesVenom is in concentrations of 0.2-200 ng/mL

3 venomous categories:

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Market Research

Snakebite Diagnosis

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CompetitionCSL Diagnostics: Snake Venom Detection Kit based on the EIA test for use in Australia ($65/test)

- Relative insensitivity- High levels of false positive

results- Cross-reactivity- Use venom from bite site

swab, but does not indicate systemic envenoming

Need StatementPractitioners need an easy, reliable, effective, and cheap way to diagnose snake bites out in the field and in clinics with basic facilities.

Optical ImmunoassayOptical detection is an easy way to detect which antivenom will work!

OIA versus ELISAFor high sensitivity and specificity

Microfluidic Channels- Insert 50uL test sample (blood/plasma/urine/wound exudates/blister

fluid/tissue homogenate) at the center of the chip- Use a heating coil to incubate the sample for 10 minutes- Use centrifugal force spinning the disc to move the sample through several

microfluidic channels:- Rinse sample with washing buffer - Drying the sample with air- Mixing with botinylated antibody solution (50uL)- Incubate for 10 minutes, additional washing and drying cycle- HRP-avidin conjugate (50uL) mixed in and incubated for 5 minutes- Washed and dried again- Substrate solution (50uL) applied to the center of the chip, incubated for 5 minutes- Observe changes in the color spots and intensity for venom specification and concentration

Device Design Principles

Device Design

Point-of-care Device

Bubble Gate Valves- Provide any necessary heating to buffers

and to speed up antibody binding- Selectively and sequentially switch valves

on/off using an external electronic system

MEMS Fabrication Process

Thanks for your attention!

Any questions?