title: Live cell imaging compatible immobilization of Chlamydomonas reinhardtii in microfluidic platform for biodiesel research.
abstract: This paper describes a novel surface immobilization method for live-cell imaging of Chlamydomonas reinhardtii for continuous monitoring of lipid droplet accumulation. Microfluidics allows high-throughput manipulation and analysis of single cells in precisely controlled microenvironment. Fluorescence imaging based quantitative measurement of lipid droplet accumulation in microalgae had been difficult due to their intrinsic motile behavior. We present a simple surface immobilization method using gelatin coating as the "biological glue." We take advantage of hydroxyproline (Hyp)-based non-covalent interaction between gelatin and the outer cell wall of microalgae to anchor the cells inside the microfluidic device. We have continuously monitored single microalgal cells for up to 6 days. The immobilized microalgae remain viable (viability was comparable to bulk suspension cultured controls). When exposed to wall shear stress, most of the cells remain attached up to 0.1 dyne/cm(2) . Surface immobilization allowed high-resolution, live-cell imaging of mitotic process in real time-which followed previously reported stages in mitosis of suspension cultured cells. Use of gelatin coated microfluidics devices can result in better methods for microalgae strain screening and culture condition optimization that will help microalgal biodiesel become more economically viable.
authors.affiliation: Division of WCU (World Class University) Multiscale Mechanical Design, School of Mechanical and Aerospace Engineering, Seoul National University, Seoul, Korea.
authors.forename: Jae Woo
authors.initials: JW
authors.lastname: Park
authors.forename: Sang Cheol
authors.initials: SC
authors.lastname: Na
authors.forename: Thanh Qua
authors.initials: TQ
authors.lastname: Nguyen
authors.forename: Sang-Min
authors.initials: SM
authors.lastname: Paik
authors.forename: Myeongwoo
authors.initials: M
authors.lastname: Kang
authors.forename: Daewha
authors.initials: D
authors.lastname: Hong
authors.forename: Insung S
authors.initials: IS
authors.lastname: Choi
authors.forename: Jae-Hyeok
authors.initials: JH
authors.lastname: Lee
authors.forename: Noo Li
authors.initials: NL
authors.lastname: Jeon
mesh_terms: D056804:Biofuels; D018914:Cells, Immobilized / Q000166:cytology*; D016825:Chlamydomonas reinhardtii / Q000166:cytology* / Q000378:metabolism*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008055:Lipids; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D008938:Mitosis / Q000502:physiology; D015203:Reproducibility of Results; D059010:Single-Cell Analysis / Q000379:methods*
chemical_list: D056804:Biofuels; D008055:Lipids
keywords: Chlamydomonas reinhardtii; biodiesel; immobilization; microfluidics