Droplet microfluidic device and methods of sensing the result of assay therein

Abstract

A method of determining the result of an assay in a microfluidic device includes the steps of: dispensing a sample droplet onto a first portion of an electrode array of the microfluidic device; dispensing a reagent droplet onto a second portion of the electrode array of the microfluidic device; controlling actuation voltages applied to the electrode array to mix the sample droplet and the reagentdroplet into a product droplet; sensing a dynamic property of the product droplet; and determining an assay of the sample droplet based on the sensed dynamic property. The dynamic property is a physical property of the product droplet that influences a transport property of the product droplet on the electrode array. Example dynamic properties of the product droplet include the moveable state, split-able state, and viscosity based on droplet properties. The method may be used to perform an amoebocyte lysate (LAL) assay.

Description

technical field

[0001] The present invention relates to droplet microfluidic devices, and in particular to electrowetting on dielectric (EWOD) devices, and more particularly to active matrix electrowetting on dielectric (AM-EWOD), and to sensing in A method of determining the dynamic properties of one or more droplets on such a device as a result of chemical or biochemical testing. Background technique

[0002] Electrowetting on dielectric (EWOD) is a well known technique for manipulating droplets of a fluid by applying an electric field. Active-matrix EWOD (AM-EWOD) refers to realizing EWOD in an active-matrix array incorporating transistors, for example by using thin film transistors (TFTs). Therefore, it is a candidate technology for digital microfluidics for lab-on-a-chip technology. An introduction to the rationale for this technology can be found in: "Digital microfluidics: is a true lab-on-a-chippossible?", R.B. Fair, Microfluid Nanofluid (2007) 3:245-281.

[0003] ...

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