title: Quantitative Assessment of Fat Levels inCaenorhabditis elegansUsing Dark Field Microscopy.
abstract: The roundwormCaenorhabditis elegansis widely used as a model for studying conserved pathways for fat storage, aging, and metabolism. The most broadly used methods for imaging fat inC. elegansrequire fixing and staining the animal. Here, we show that dark field images acquired through an ordinary light microscope can be used to estimate fat levels in worms. We define a metric based on the amount of light scattered per area, and show that this light scattering metric is strongly correlated with worm fat levels as measured by Oil Red O (ORO) staining across a wide variety of genetic backgrounds and feeding conditions. Dark field imaging requires no exogenous agents or chemical fixation, making it compatible with live worm imaging. Using our method, we track fat storage with high temporal resolution in developing larvae, and show that fat storage in the intestine increases in at least one burst during development.
authors.affiliation: Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
authors.forename: Anthony D
authors.initials: AD
authors.lastname: Fouad
authors.affiliation: Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
authors.forename: Shelley H
authors.initials: SH
authors.lastname: Pu
authors.affiliation: Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
authors.forename: Shelly
authors.initials: S
authors.lastname: Teng
authors.affiliation: Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
authors.forename: Julian R
authors.initials: JR
authors.lastname: Mark
authors.affiliation: Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
authors.forename: Moyu
authors.initials: M
authors.lastname: Fu
authors.affiliation: Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
authors.forename: Kevin
authors.initials: K
authors.lastname: Zhang
authors.affiliation: Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Huang
authors.affiliation: Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
authors.forename: David M
authors.initials: DM
authors.lastname: Raizen
authors.affiliation: Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104 fangyen@seas.upenn.edu.|Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
authors.forename: Christopher
authors.identifier: 0000-0002-4568-3218
authors.initials: C
authors.lastname: Fang-Yen
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D005223:Fats / Q000378:metabolism*; D007814:Larva; D066292:Lipid Droplets; D050356:Lipid Metabolism; D008853:Microscopy / Q000379:methods; D009154:Mutation; D013194:Staining and Labeling
chemical_list: D005223:Fats
keywords: C. elegans; Nile Red; Oil Red O; dark field; fat