Disclosed herein are two related techniques for digital microfluidic (DMF) processing of liquids that rely on electrostatic actuation of fluid through a strip of solid, porous media. In the first technique, droplets in a DMF device containing particles of different sizes are driven through a solid porous medium, allowing for filtering, concentration, and recovery of the particles into droplets on the basis of size. In the second technique, an aliquot of liquid media is loaded directly onto a solid porous medium, where it is wicked into a DMF device, such that the filtrate can be collected into droplets. Both techniques may be useful for generating plasma from whole blood on a DMF device, an operation that will have far-reaching implications for diagnostic applications of digital microfluidics.

The present invention provides microfluidic pScreen devices for quantifying the concentration of DNA fragments in a liquid sample by using magnetic-responsive silica micro-beads and nonmagnetic-responsive silica micro-beads. The devices of the present invention allow for rapid, simple and inexpensive quantification of DNA fragment concentration in a sample. The devices do not require complex instrumentation and can be performed in less than three minutes. Moreover, they are compatible with complex samples including, without limitation, unpurified PCR amplification products, and thus can be expected to seamlessly integrate into various common molecular biology techniques and workflows.

An apparatus includes a fluidic circuit, a bypass fluidic circuit, a first set of fluid wells, a second set of fluid wells, a first valve, and a second valve. The first valve operatively associated with the first set of fluid wells such that the first selectively fluidly connects any one of the first set of fluid wells to a first valve outlet. The second valve operatively associated with the fluidic circuit, the bypass fluidic circuit, the first valve outlet, and the second set of fluid wells such that the second valve selectively fluidly connects any one of the second set of fluid wells and the first valve outlet to the fluidic circuit or the first valve outlet to the bypass fluidic circuit.

A passive, hydrodynamic technique implemented using a microfluidic device to perform co-encapsulation of samples in droplets and sorting of said droplets is described herein. The hydrodynamic technique utilizes laminar flows and high shear liquid-liquid interfaces at a microfluidic junction to encapsulate samples in the droplets. A sorting mechanism is implemented to separate sample droplets from empty droplets. This technique can achieve a one-one-one encapsulation efficiency of about 80% and can significantly improve the droplet sequencing and related applications in single cell genomics and proteomics.

A particle analysis system includes an inlet; an inertial focusing microchannel disposed in a substrate and having a downstream expanding region at a distal end, where the inlet is connected to a proximal end of the microchannel; a plurality of outlets connected to the microchannel at the downstream expanding region; a plurality of fluidic resistors, where each fluidic resistor is connected to a respective outlet; and a particle analyzer configured to measure a size and a position of particles in the microchannel. A particle sorting system includes an inlet; an inertial focusing microchannel disposed in a substrate and having a downstream expanding region at a distal end, where the inlet is connected to a proximal end of the microchannel; a plurality of outlets connected to the microchannel at the downstream expanding region; and a plurality of fluidic resistors, where each fluidic resistor is connected to a respective outlet.

A fluid sample collection card in one embodiment includes an absorbent strip including a sample application portion, a first absorbent strip portion extending directly from the sample application portion, and a second absorbent strip portion extending directly from the sample application portion and spaced apart from the first absorbent strip portion by the sample application portion, a non-absorbent layer positioned beneath the absorbent strip, and a sample application portion indicium configured to identify the sample application portion.

Apparatus, system and method for dispensing a particle-laden fluid from a fluid holding and dispensing micro-feature. In some implementations, the apparatus includes: a chamber having one or more surfaces that define a volume to receive fluid containing particulate matter, and an outlet port to dispense at least a portion of the fluid from the chamber. The outlet port may have a normal vector that, when the apparatus is positioned to dispense the fluid, is substantially perpendicular to gravity. The apparatus may be used to measure a number of individual particles from the fluid that flow through the outlet port over a period of them, measure a total volume of the fluid dispensed through the outlet port over the period of time, and calculate a concentration of the particulate matter within the chamber. In some implementations, the particle-laden fluid may be whole blood.

In certain embodiments, the present invention provides amplification methods in which nucleotide tag(s) and, optionally, a barcode nucleotide sequence are added to target nucleotide sequences. In other embodiments, the present invention provides a microfluidic device that includes a plurality of first input lines and a plurality of second input lines. The microfluidic device also includes a plurality of sets of first chambers and a plurality of sets of second chambers. Each set of first chambers is in fluid communication with one of the plurality of first input lines. Each set of second chambers is in fluid communication with one of the plurality of second input lines. The microfluidic device further includes a plurality of first pump elements in fluid communication with a first portion of the plurality of second input lines and a plurality of second pump elements in fluid communication with a second portion of the plurality of second input lines.

A cell sorting method includes: obtaining a cervical sample of a pregnant mammal, the cervical sample including placental trophoblast cells and cervical cells; removing the mucus of the cervical sample; dispersing the placental trophoblast cells and the cervical cells; centrifuging the cervical sample to remove the supernatant of the cervical sample; and using a dielectrophoretic chip to perform sorting on the cervical sample, so as to sort out the placental trophoblast cells from the cervical cells.

Microfluidic structures and methods for manipulating fluids and reactions are provided. Such structures and methods may involve positioning fluid samples, e.g., in the form of droplets, in a carrier fluid (e.g., an oil, which may be immiscible with the fluid sample) in predetermined regions in a microfluidic network. In some embodiments, positioning of the droplets can take place in the order in which they are introduced into the microfluidic network (e.g., sequentially) without significant physical contact between the droplets. Because of the little or no contact between the droplets, there may be little or no coalescence between the droplets. Accordingly, in some such embodiments, surfactants are not required in either the fluid sample or the carrier fluid to prevent coalescence of the droplets. Structures and methods described herein also enable droplets to be removed sequentially from the predetermined regions.