Abstract: This invention provides methods and systems for detecting interaction between members of a binding pair. The method involves associating one member of the binding pair with a nanoparticle and detecting the interaction between the two molecules by back-scattering interferometry.

Abstract: A microfluidic system includes a chip with a microfluidic channel opening onto a chip inlet and a chip outlet. The channel has a sensing area and fluid delivery area. A fluidic adaptor channel opening onto an adaptor inlet and an adaptor outlet can receive a pipette tip through the adaptor inlet wherein receipt of the pipette tip into the adaptor channel creates a direct fluid path between the pipette tip and the channel and wherein the microfluidic system is configured for sensing in the sensing area by interferometry.

Abstract: Devices and methods for detecting interaction between components associated with lipid membranes and analytes are described herein. In certain methods, a surface of a compartment of a device is coated with a material that attaches to lipid membrane from a sample. An analyte is introduced and interaction is detected, for example, by back scattering interferometry. In another method, a surface is passivated with a material that does not bind a lipid membrane. A sample is introduced that contains a membrane comprising a component for testing and an analyte. Interaction is detected. In a third method, a channel is filled with a first liquid that does not comprise a lipid membrane. A bolus of a second liquid that comprises a membrane comprising a component for testing and an analyte is introduced under laminar flow conditions so that a leading edge of the second liquid does not completely displace the first liquid in a sensing area that is interrogated by optical methods, for example, a laser.

Abstract: This invention provides an interferometric detection device configured to maintain a temperature of a sensing area to within 20 m° C. of a first target temperature and to maintain a temperature of the medium within 500 m° C. of a second target temperature The device can do so under conditions in which ambient temperature changes from 0.1° C. to 5° C. over 5 minutes.

Abstract: This invention provides an interferometric detection device configured to maintain a temperature of a sensing area to within 20 m° C. of a first target temperature and to maintain a temperature of the medium within 500 m° C. of a second target temperature The device can do so under conditions in which ambient temperature changes from 0.1° C. to 5° C. over 5 minutes.

Abstract: This invention provides methods and devices for analyzing interference patterns. The methods include fitting a Gaussian distribution to a cross correlation of two patterns from interferometric analysis of a liquid at a first and second time; identifying a positional shift of the pattern by comparing a selected value of the Gaussian distributions of the pattern at the first and second times; and determining a change in refractive index of the liquid from the positional shift. In another aspect, a method of extending the dynamic range of an interferometric data set is provided that comprises linearizing the data set, for example, using the arcsine function.

Abstract: This invention provides a device and method for collection and analysis of heterogeneous samples in a single sample container by back scattering interferometry. The sample container is configured to allow collection of a heterogeneous sample, such as blood, from a subject, separation of insoluble materials, such as blood cells by, for example, centrifugation, and mounting on a back scattering interferometer for analysis. In certain embodiments the container is a capillary tube and the interferometer comprises a mounting to hold the capillary tube in position for analysis. The device and method allow point-of-care analysis of samples.

Abstract: Compositions and methods of modifying surfaces using hydroxyl terminated PEG are described herein. The surfaces so modified are useful in detection of synthetic and natural product organic molecules, organometallics, biomolecules, particles, or cells.

Abstract: This invention provides an interferometer for detecting analyte in a microfluidic chip. The device maintains a stable temperature at the chip with variation of no more than 5 microdegrees C. and/or no more than 20 microdegrees C. in the medium through which the optical train travels from a source of coherent light to the chip when ambient temperature changes up to 5 degrees centigrade over five minutes. The device comprises thermally isolated compartments that hinder heat transfer from one part of the instrument to another and temperature regulators that regulate temperature of the chip and the optical train compartment as a function of temperatures at the chip, in the compartment, and ambient. The invention also provides a microfluidic system that can deliver 1 microliter of sample to a sensing area with loss in analyte concentration of less than 5%. The device has an adaptor that mates with a micropipette tip and short channel length and small volume to the sensing area.