IDENTIFYING SNAKE SPECIES INVOLVED IN BITES

New Technology, New Options

Disclaimer: I am not involved with any of the companies that make products covered in this presentation

ELISA (Enzyme-linked immunoassay)

• Inexpensive (relative! c. $275 for 3 reactions)• relatively easy to perform• fast (< 30 mins)• uses stable reagents• sensitivity of < 1 ng/ml

ELISA (Enzyme-linked immunoassay)

• False positives through low specificity/cross reactivity ESPECIALLY in regions with diverse snake faunas

• False negatives through upper limit of detectability (c. 1 mg/ml in some spp)

• first application to snakebite c. 35 years ago • Snake venom detection kit (SVDK) issued by CSL,

Australia since 1988 is the still the only commercial diagnostic kit

• Alternative biosensor approach advocated by Selvanayagam & Gopalakrishnakone in Toxicon in 1999.

http://www.blitzmenow.com

LABEL-FREE Kinetic profiling of immunotherapeuticsVaccine efficacy testing

Drop. Read. Done. Genius!Eg. BLItzTM system

1. Pipette a 4 µL drop of sample into the sample holder. 2. Install a biosensor.

3. Select your assay and click GO. Results appear immediately!

Disposable biosensor (can be re-used): c. $4.50/assay

Non-denaturing, minimises non-specific binding

Exceptional specificity even for crude media

Bio-layer interferometry (BLI)

Real-time data

DNA diagnostics

Is this what it takes?

1. Sample collection, storage and extractionWhatman™ FTA cards:Collect, archive, transport, and purify nucleic acids at room temperatureminimal handling, streamlined, efficient workflow for sample collection and analysis.$3-5/sample

(30 mins)

2. Biomarker amplificationReady-to-go PCR tubes: just add sample (c. $1.50/sample)Pre-dispensed, room temp stable, reliable and reproducibleCustom formats including primers Also available in RT-PCR format for single-step amplification from RNAStill needs a conventional PCR machine (thermal cycler): c. $1700

PCR CYCLER: LavaAmp (prototype)20-25 reactions maxPowered by 4 x AA batteries or USB cable$300-$500, aiming for $100Some development problems delaying it?

lava-amp.com

3. Vizualisation: FlashGel® System (c. $430, plus c. $10/gel running costs)5 minute separation and recovery

http://dx.doi.org/10.1016/j.jip.2010.06.001

TOTAL COST PER SAMPLE: $15-17Equipment: c.£2000 (and can be used for other diagnostics as well