University of California, Davis

6 ARTICLES PUBLISHED IN JoVE

Bioengineering

Microfluidic Mixers for Studying Protein Folding

Steven A. Waldauer¹, Ling Wu¹, Shuhuai Yao², Olgica Bakajin³, Lisa J. Lapidus¹

¹Department of Physics and Astronomy, Michigan State University, ²Department of Mechanical Engineering, Hong Kong University of Science and Technology, ³Center for Biophotonics, University of California, Davis

In this work we explain the fabrication and use of a microfluidic mixer capable of mixing two solutions in ~8 μs. We also demonstrate the use of these mixers with spectroscopic detection using UV fluorescence and fluorescence resonance energy transfer (FRET).

Bioengineering

On-Chip Endothelial Inflammatory Phenotyping

J. Sherrod DeVerse^*1, Keith A. Bailey^*1, Greg A. Foster¹, Vaishali Mittal¹, Stuart M. Altman¹, Scott I. Simon¹, Anthony G. Passerini¹

¹Department of Biomedical Engineering, University of California, Davis

Microfluidic flow chambers etched by photolithography and fabricated from PDMS are applied to probe functional outcomes associated with EC dysfunction and inflammation. In a representative experiment, the ability of differential shear stress to modulate monocytic cell adhesion to cytokine activated EC monolayers is demonstrated.

JoVE Journal

Quantitative Analysis of Autophagy using Advanced 3D Fluorescence Microscopy

Chun A. Changou^1,2, Deanna L. Wolfson², Balpreet Singh Ahluwalia^2,3, Richard J. Bold^4,5, Hsing-Jien Kung^5,6, Frank Y.S. Chuang^1,2,5

¹Department of Biochemistry and Molecular Medicine, University of California, Davis , ²NSF Center for Biophotonics Science & Technology, University of California, Davis , ³University of Tromsø, ⁴Department of Surgery (Division of Surgical Oncology), University of California, Davis , ⁵UC Davis Comprehensive Cancer Center, University of California, Davis , ⁶Department of Biological Chemistry, University of California, Davis

Autophagy is a ubiquitous process that enables cells to degrade and recycle proteins and organelles. We apply advanced fluorescence microscopy to visualize and quantify the small, but essential, physical changes associated with the induction of autophagy, including the formation and distribution of autophagosomes and lysosomes, and their fusion into autolysosomes.

Bioengineering

Microfabrication of Nanoporous Gold Patterns for Cell-material Interaction Studies

Pallavi Daggumati¹, Ozge Kurtulus², Christopher Abbott Reece Chapman³, Damla Dimlioglu¹, Erkin Seker¹

¹Department of Electrical and Computer Engineering, University of California, Davis , ²Department of Chemical Engineering and Materials Science, University of California, Davis , ³Department of Biomedical Engineering, University of California, Davis

We report on techniques to micropattern nanoporous gold thin films via stencil printing and photolithography, as well as methods to culture cells on the microfabricated patterns. In addition, we describe image analysis methods to characterize morphology of the material and the cultured cells using scanning electron and fluorescence microscopy techniques.

Biology

In Vitro SUMOylation Assay to Study SUMO E3 Ligase Activity

Wan-Shan Yang¹, Mel Campbell², Hsing-Jien Kung^2,3,4,5, Pei-Ching Chang^1,6

¹Institute of Microbiology and Immunology, National Yang-Ming University, ²UC Davis Cancer Center, University of California, Davis, ³Department of Biochemistry and Molecular Medicine, University of California, Davis, ⁴Institute for Translational Medicine, College of Medical Science and Technology, Taipei Medical University, ⁵Division of Molecular and Genomic Medicine, National Health Research Institutes, ⁶Center for Infectious Disease and Cancer Research, Kaohsiung Medical University

Unlike ubiquitin ligases, few E3 SUMO ligases have been identified. This modified in vitro SUMOylation protocol is able to identify novel SUMO E3 ligases by an in vitro reconstitution assay.

Immunology and Infection

A Mouse Model to Assess Innate Immune Response to Staphylococcus aureus Infection

Leif S. Anderson¹, Mack B. Reynolds¹, Kathryn R. Rivara¹, Lloyd S. Miller², Scott I. Simon¹

¹Department of Biomedical Engineering, University of California Davis, ²Department of Dermatology, Johns Hopkins University School of Medicine

An approach is described for real-time detection of the innate immune response to cutaneous wounding and Staphylococcus aureus infection of mice. By comparing LysM-EGFP mice (which possess fluorescent neutrophils) with a LysM-EGFP crossbred immunodeficient mouse strain, we advance our understanding of infection and the development of approaches to combat infection.