Methods and apparatus for processing a sample of biomolecular analyte using a microfabricated device

Abstract

A technique processes a sample of biomolecular analyte. The technique uses an apparatus having a support assembly that receives and supports a test module, a load assembly that loads the sample of biomolecular analyte onto the test module, an electrophoresis assembly that applies a current to the test module such that components within the sample separate by electrophoresis, and a controller that controls operations of the load assembly and the electrophoresis assembly. The load assembly and the electrophoresis assembly are coupled to the support assembly. The controller controls the operation of the load assembly in an automated manner. Preferably, the test module includes a dielectric plate member having an upper planar surface and a lower planar surface that is spaced apart from and coplanar with the upper planar surface. The dielectric plate member has at least one set of channels that includes an injection channel and a separation channel. The injection channel extends from the upper planar surface to the lower planar surface. The separation channel extends within the dielectric plate member in a plane parallel with the upper and lower planar surfaces and intersects the injection channel.

Description

RELATED APPLICATIONS [0001] This application is a divisional of application Ser. No. 09 / 768,075 filed Jan. 23, 2001 which is a divisional of application Ser. No. 09 / 153,215, filed Sep. 14, 1998 (now U.S. Pat. No. 6,207,031) which claims the benefit of U.S. Provisional Application No. 60 / 058,798, filed on Sep. 15, 1997. [0002] The entire teachings of the above applications are incorporated herein by reference.GOVERNMENT SUPPORT [0003] The invention was supported, in whole or in part, by Grant No. RO1 HG01389 from the National Institutes of Health and Grant No. F49620-95-1-0165 from the Defense Advanced Research Projects Agency / Air Force Office of Scientific Research. The Government has certain rights in the invention.BACKGROUND OF THE INVENTION [0004] The human genome includes stretches of DNA composed of short tandem repeats (STRs). The analysis of such STRs is an important tool for genetic linkage studies, forensics, and new clinical diagnostics because STRs are abundant and their ...

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Benefits of technology

[0014] In general, the term “biomolecular analyte” refers to both non-synthetic and synthetic nucleic acids (e.g., DNA and RNA) and portions thereof, and biological proteins. Described herein are practical ultra-fast techniques for allelic profiling of such biomolecular analyte. In particular, the techniques involve using a microfluidic electrophoresis device to analyze short tandem repeats (STRs) within a DNA sample. An assay method of the present invention has made it possible to rapidly achieve baseline-resolved electrophoretic separations of single-locus STR samples. In one embodiment, the assay permits baseline-resolved electrophoretic separations of single-locus STR samples in approximately 30 seconds. In addition, analysis of samples (e.g., PCR samples) containing loci defined or characterized by an STR which differs in the number or repeats is performed rapidly (e.g., at a rate which represents a 10-to-100-fold improvement in speed relative to capillary or slab gel systems) using the allelic profiling assay described herein. For example, analyses of PCR samples containing the four loci CSF1PO, TPOX, THO1 and vWA (abbreviated as CTTv) can be performed in less than two minutes. This constitutes a 10-to-100-fold improvement in speed relative to capillary or slab gel systems.

[0027] Preferably, the step of positioning the electromagnetic loading device includes the step of actuating a robotic assembly that supports the electromagnetic loading device such that the electromagnetic loading device moves to a programmed position relative to the test plate. This allows the sample to be positioned accurately and consistently from test to test.

[0031] Preferably, the test module assembly includes a heating device, supported by the housing, that provides heat to the dielectric plate member when power is provided to the heating device. The heat facilitates the separation of components within the sample during electrophoresis.

[0034] Preferably, the dielectric plate member includes multiple sets of channels. Each set of channels includes an injection channel and a separation channel. The injection channel of each set extends from the upper planar surface to the lower planar surface. The separation channel of each set extends within the dielectric plate member in a plane parallel with the upper and lower planar surfaces and intersects the injection channel of that set. The injection channels of the multiple sets of channels may be parallel with each other. These features of the invention increase the channel density (i.e., the number of channel sets per unit area of the plate member) of the dielectric plate member enabling more tests to be scanned by an individual scanner in a fixed position relative to the dielectric plate member. Furthermore, the orthogonal orientation of the injection channels (relative to the plane of the plate member) improves initial separation of the components within the sample during electrophoresis in the direction of the injection channel.

Problems solved by technology

Nevertheless, significant decreases in electrophoretic run-times would greatly increase the speed of STR analysis.

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