Biophysical Society Thematic Meeting

Biophysics in the Understanding, Diagnosis, and Treatment of Infectious Diseases Poster Abstracts

39-POS

Board 39

Lester Sigauke

University of Cape Town, Cape Town, South Africa.

Withdrawn

40-POS

Board 40

Portable Immuno-Capture Device for Early Stage Typhoid Diagnosis in 6 hrs

Saurabh Singh

, Mohita Mukhopadhyaya, Neha Sharma, Vivekanandan Perumal, Ravikrishnan

Elangovan.

Indian Institute of Technology Delhi, New Delhi, India.

Typhoid fever is a global health problem and is caused by Salmonella typhi, a gram-negative

bacterium and a very similar Salmonella serotype paratyphi A. Currently diagnosis of typhoid

done by (a) blood culture test (b) detection of specific antibody response by widal®, typhidot®

and tubex® assay. Antibody response based assay can confirm typhoid only after 4-7 days of

infection. The blood culture assay is the gold standard for typhoid diagnosis but has limitation of

long (48-78 hrs) processing time for final results. Typhoid patients have the causative organism

S. typhi in their blood but its concentration is as low as 1 CFU/ml in early stage of infection, and

there is no existing diagnostic method to detect this lower concentration in same day. We have

developed a portable device for early stage typhoid diagnosis within 6 hr. This process involves

culture growth of patient blood in broth media for 5.5 hrs and then immuno-magnetic enrichment

of the target cells using portable device. The enriched target cells was then visually confirmed by

lateral flow immunoassay.

Portable device and capture chip:

To enrich target cells in cultured sample, we have developed

a portable immuno-magnetic enrichment device and a capture chip. The device consists of an

automated linear positioner with a magnet cassette mounted on it. Specific arrangement of

permanent magnets in cassette allow rapid magnetic capture. Capture chip can be placed on the

cassette after loading the sample, pre-incubated with immuno-magnetic particles. Now the linear

movement of magnet cassette concentrate target cells into a 50µl recovery chamber of chip.