Christopher M Silva

US Patent:

6456734, Sep 24, 2002

Filed:

Jun 5, 1998

Appl. No.:

09/092316

Inventors:

Douglas C. Youvan - San Jose CA
Christopher M. Silva - Sunnyvale CA
Edward J. Bylina - San Jose CA
William J. Coleman - Moutain View CA
Michael R. Dilworth - Santa Cruz CA
Mary M. Yang - San Jose CA

Assignee:

Kairos Scientific, Inc. - San Diego CA

International Classification:

G06K 900

US Classification:

382128, 382100, 382132, 382133

Abstract:

Imaging hardware, software, calibrants, and methods are provided to visualize and quantitate the amount of Fluorescence Resonance Energy Transfer (FRET) occurring between donor and acceptor molecules in epifluorescence microscopy. The MicroFRET system compensates for overlap among donor, acceptor, and FRET spectra using well characterized fluorescent beads as standards in conjunction with radiometrically calibrated image processing techniques. The MicroFRET system also provides precisely machined epifluorescence cubes to maintain proper image registration as the sample is illuminated at the donor and acceptor excitation wavelengths. Algorithms are described that pseudocolor the image to display pixels exhibiting radiometrically-corrected fluorescence emission from the donor (blue), the acceptor (green) and FRET (red). The method is demonstrated on samples exhibiting FRET between genetically engineered derivatives of the Green Fluorescent Protein (GFP) bound to the surface of Ni chelating beads by histidine-tags.

US Patent:

59142456, Jun 22, 1999

Filed:

Jun 16, 1998

Appl. No.:

9/098202

Inventors:

Edward J. Bylina - San Jose CA
William J. Coleman - Mountain View CA
Michael R. Dilworth - Santa Cruz CA
Christopher M. Silva - Sunnyvale CA
Mary M. Yang - San Jose CA
Douglas C. Youvan - San Jose CA

Assignee:

Kairos Scientific Inc. - Santa Clara CA

International Classification:

C12Q 144
C12Q 137
C12Q 154
C12Q 100

US Classification:

435 19

Abstract:

A MicroColonyImager instrument and solid phase methods to screen cells expressing mutagenized enzymes for enhanced activity. The MicroColonyImager instrument and methods permit high throughput screening of enzyme libraries by time course analyses of single-pixels, using either absorption, fluorescence or FRET. This high throughput assay can detect small differences in enzyme rates within microcolonies grown at a nearly confluent density on an assay disk. Each microcolony is analyzed simultaneously at single-pixel resolution, requiring less than 100 ml substrate/measurement. By simultaneously assaying different substrates tagged with spectrally distinct chromogenic or fluorogenic reporters, the substrate specificity of an enzyme can be changed.