100428 ug2

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Developing near real-time DEP hardware

Nahrizul Adib Kadrin.kadri@surrey.ac.uk

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What’s DEP?

• Electrophoresis– Charged particles moving in uniform field

D ie lec tric pa rtic le

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What’s DEP?

• Dielectrophoresis– Dielectric particles moving in non-uniform field

Dielectric particle

Die lectric particle

Positive DEP Negative DEP

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What’s DEP?

• Theory bit– (the only time an equation appears in this

presentation… promise!)

232F E)K(Rer m

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**

2)(

mp

mpK

j

*

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What’s DEP used for?

• Cell movement can be manipulated by frequency changes, so DEP is good for cell collection and sorting

Morgan et al. Biophysical Journal 77 (1999) 516-525

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What’s DEP used for?

• Compare cell viability

G.H. Markx, C.L. Davey / Enzyme and Microbial Technology 25 (1999) 161–171

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What’s DEP used for?

• Compare effects of chemicals on cells

F.H. Labeed et al. / Biochimica et Biophysica Acta 1760 (2006) 922–929

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What’s DEP used for?

• Predict cell properties

232F E)K(Rer m

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What’s DEP used for?

• Everything’s fine and dandy BUT DEP is not available commercially, nor used widely– Despite being described back in 1950s

• …but why?– Small assays only

• Restricted to research use

– Time consuming• One spectrum takes 40-60 minutes

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What’s DEP used for?

• The answer(?): Multiple experiments at the same time!– Different

frequencies, or– Same frequencies

10kHz 2MHz

300um

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http://www.youtube.com/watch?v=lLZbr3vP-Zs

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DEP: The setup

• What’s needed:

Imaging/recording device

Microscope

Electrode

Cells

Signal generator

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DEP: The (new) setup

• What’s (really) needed:

Imaging/recording device

Microscope

Electrode

Cells

Multiple output signal generator

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Real-time DEP

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Real-time DEP

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Frequency (Hz)

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DEP plots for Jurkat cells treated with valinomycin 100402 (10 mS/m)

Control

Valinomycin

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Real-time DEP

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Frequency (Hz)

DEP spectrum for Jurkat cells treated with valinomycin 091216

Time (min)

Mod

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hift

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Real-time DEP

• That’s it! (for now, hopefully)

• Any questions: – n.kadri@surrey.ac.uk– facebook.com/nahrizuladib