Cheng N Lee

US Patent:

6929730, Aug 16, 2005

Filed:

May 1, 2002

Appl. No.:

10/135385

Inventors:

Cheng Sheng Lee - Ellicott City MD, US
Donald Lad DeVoe - Bethesday MD, US

International Classification:

G01N027/447
G01N027/453

US Classification:

204451, 204601

Abstract:

One embodiment of the invention relates to a microfluidic apparatus for performing two dimensional biomolecular separations. According to one aspect of the invention, after a first dimension separation in a first microchannel, the sample material is electrokinetically and simultaneously transferred to an array of microchannels in the second dimension (e. g. , by changing the electric potentials at the reservoirs connected to the microchannels). Preferably any separation accomplished in the first dimension is completely retained upon transfer to the second dimension. According to another aspect of the invention, the separation in the second dimension is performed using a temperature gradient (e. g. , a spatial or temporal temperature gradient). According to one embodiment of the invention, the biomolecular material comprises DNA and the first dimension separation is a sized-based separation and the second dimension separation is a sequence-based separation.

US Patent:

6974526, Dec 13, 2005

Filed:

May 1, 2002

Appl. No.:

10/135386

Inventors:

Cheng Sheng Lee - Ellicott City MD, US
Don DeVoe - Bethesda MD, US

Assignee:

Calibrant Biosystems, Inc. - Rockville MD
The University of Maryland - Riverdale MD

International Classification:

G01N027/447
G01N027/453

US Classification:

204451, 204601

Abstract:

The invention provides a microfluidic apparatus for performing 2-D biomolecular separations. The microfluidic 2-D device may include first and second planar substrates which include at least a first dimension microchannel extending in a first direction and an array of second dimension microchannels extending in a second direction, preferably, orthogonal to the first dimension. The ends of at least some of the microchannels are in fluid communication with a plurality of reservoirs. The substrates may further include a number of microchannels and reservoirs. The reservoirs are in electrical communication with a plurality of electrodes and voltage power sources. The device enables two dimensional separations of proteins and other biomolecules. According to another aspect of the invention, an isoelectric point based separation is enabled in a first dimension, and a size based separation in a second dimension.

US Patent:

7070682, Jul 4, 2006

Filed:

Jan 15, 2002

Appl. No.:

10/047759

Inventors:

Cheng Lee - Ellicott City MD, US
Don DeVoe - Bethesda MD, US

International Classification:

G01N 27/447
G01N 27/453

US Classification:

204462, 204613

Abstract:

The invention relates to an apparatus for performing gel protein extractions and methods of using the apparatus.

US Patent:

7641780, Jan 5, 2010

Filed:

Mar 23, 2005

Appl. No.:

11/086400

Inventors:

Cheng Sheng Lee - Ellicott City MD, US
Don DeVoe - Bethesda MD, US

Assignee:

Calibrant Biosystems, Inc. - Rockville MD
The University of Maryland - Riverdale MD

International Classification:

G01N 27/453
G01N 30/02
B01L 3/00

US Classification:

204601, 422 70, 422 99

Abstract:

The invention provides a microfluidic apparatus for performing 2-D biomolecular separations. The microfluidic 2-D device may include first and second planar substrates which include at least a first dimension microchannel extending in a first direction and an array of second dimension microchannels extending in a second direction, preferably, orthogonal to the first dimension. The ends of at least some of the microchannels are in fluid communication with a plurality of reservoirs. The substrates may further include a number of microchannels and reservoirs. The reservoirs are in electrical communication with a plurality of electrodes and voltage power sources. The device enables two dimensional separations of proteins, DNA and other biomolecules. According to another aspect of the invention, an array of tertiary microchannels extending in a third direction may be utilized.

US Patent:

20030127329, Jul 10, 2003

Filed:

Jun 1, 2002

Appl. No.:

10/159914

Inventors:

Donald DeVoe - Bethesda MD, US
Cheng Lee - Ellicott City MD, US

International Classification:

G01N027/26
G01N027/447

US Classification:

204/454000, 204/451000, 204/601000

Abstract:

One embodiment of the invention relates to a microfluidic apparatus for controlling fluid flow velocity during electroosmotic flow. According to one aspect of the invention, a voltage applied to a gate electrode modulates flow velocity within an associated microchannel, where the gate voltage is separate from any voltage used to induce electroosmotic flow. According to another aspect of the invention, the flow control apparatus combines multiple gate electrodes to control flow in a microfluidic network. According to one embodiment of the invention, the flow control apparatus is fabricated in a planar silicon substrate. According to another embodiment of the invention, the flow control apparatus is fabricated using polymer materials.

US Patent:

20060019399, Jan 26, 2006

Filed:

Jul 1, 2005

Appl. No.:

11/171427

Inventors:

Brian Balgley - Annandale VA, US
Jonathan Cooper - Walkersville MD, US
Cheng Lee - Ellicott City MD, US
Donald DeVoe - Bethesda MD, US

International Classification:

G01N 33/00

US Classification:

436086000

Abstract:

Disclosed is a system for performing multiple analyses of protein and/or peptide samples and correlating the results of the analyses. The system comprises a sample inlet, a splitter means, at least two sample delivery capillaries, at least two sample deposition tools, and at least two sample collectors, wherein said splitter means is in fluid communication with the sample inlet and the sample delivery capillaries, and wherein liquid flow entering the splitter means is split into a number of sub-flows equal to the number of sample delivery capillaries. In one preferred embodiment, at least one microenzyme reactor is interfaced to a first sample delivery capillary in order to digest a protein sample within the capillary, while a second sample delivery capillary does not contain a microenzyme reactor, thereby enabling correlated analysis of the same protein sample in digested and undigested form. Methods for performing two or more analyses of protein and/or peptide samples and correlating the results of the analyses are also disclosed.

US Patent:

20060192107, Aug 31, 2006

Filed:

Oct 5, 2005

Appl. No.:

11/242842

Inventors:

Donald DeVoe - Bethesda MD, US
Yingxin Wang - Columbia MD, US
Cheng Lee - Ellicott City MD, US
Yan Li - Bethesda MD, US

International Classification:

B01D 59/44

US Classification:

250288000

Abstract:

Disclosed are an apparatus, system, and method for performing electrospray of biomolecules, particularly peptides, polypeptides, and proteins. The apparatus comprises at least (1) a microfluidic substrate for containing an electrospray microchannel for delivering analyte molecules to a side edge of the substrate, and (2) a porous membrane attached to the side edge for performing electrospray from the exposed membrane surface. In one preferred embodiment, the exposed membrane surface is positioned above a target surface for depositing analyte molecules onto the target surface by electrospray. In another preferred embodiment, a proteolytic enzyme is bound to the porous membrane for performing protein digestion during electrospray.

US Patent:

53345371, Aug 2, 1994

Filed:

Nov 14, 1991

Appl. No.:

7/791309

Inventors:

Cheng S. Lee - Columbia MD
Ping Y. Huang - Baltimore MD

Assignee:

The University of Maryland - College Park MD

International Classification:

G01N 33543
G01N 33536

US Classification:

436518

Abstract:

The complexing of an antibody-antigen binding pair is determined by observing the change in fluorescence of a pH-sensitive fluorochrome attached to one of the members of the binding pair. When the binding is conducted in a solution having a pH other than the isoelectric point of the antibody, there will be a change in the pH of the microenviromnent surrounding the fluorochrome. This change will correspond to a change in the observed fluorescent intensity. Either member of the binding pair can be labeled, and combined with that member whose presence is suspect, in an immunoassay.