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*CIL – Cell Image Library accession number. Please use this to reference an image.

CIL:25824*  Cite 

Chromophore-assisted laser inactivation (CALI) inactivates target proteins by generating reactive photoproducts such as reactive oxygen species (ROS) by intense irradiation of photosensitizer chromophores, such as EGFP. Rat2 cells expressing soluble EGFP, were subjected to CALI to test for nonspecific laser-induced effects. After administration of a 100-ms dose of 1.5 mW/[μm]2 laser light, no morphological changes were visualized, as as seen in this DIC time-lapse movie. This and CIL# 25823 are control movies for CIL# 25821, 25822. This movie is Movie4 in Supporting Information in Proc Natl Acad Sci (2007) 104: 6702-6707.

Technical Details

EGFP-CP CALI experiments were performed by using a Spectra Physics Stabilite 2017 (Spectra Physics Laser Incorporated) argon ion laser (488 nm line, 2 W of beam power at the laser head) focused onto a 23.4 μm diameter spot (1/[e]2 diameter) through a 60x 1.45 N.A. PlanApo TIRF objective (Olympus). Irradiation was controlled with a fast Uniblitz (Vincent Associates) shutter. Laser power at the specimen plane dropped to 625 mW because of optical losses and was measured by placing the sensor of a laser power meter (Model FM with LS 10 head, Coherent Inc.) directly above the objective. Irradiation time was 100 ms, resulting in a 62.5-mJ dose of energy for the CALI experiment. Laser light was focused onto the specimen plane through a 488-nm laser filter set (Z488/10, HQ525/50, Z488RDC, Chroma Technology Corporation). Rat2 cells were plated onto 35-mm glass-bottomed dishes coated with 10 mg/ml fibronectin. Twenty minutes after plating, media was changed to DMEM without phenol red supplemented with 10% FBS, l-glutamine, and penicillin/streptomycin. DIC time-lapse imaging was performed on an Olympus IX81 inverted microscope equipped with a cooled 12-bit digital CCD camera (Sensicam QE, Cooke Corporation), and a heated chamber (Werner Instruments) with CO2 flow. All images were acquired with MetaMorph software (Version 6.0, Universal Imaging Corporation).

Biological Sources
NCBI Organism Classification
Rattus norvegicus
Cell Type
Cell Line
Cellular Component
intracellular organelle
Eric A. Vitriol
Andrea C. Uetrecht
Feimo Shen
Ken Jacobson
James E. Bear
Proc Natl Acad Sci (2007) 104: 6702-6707.
Digital Object Identifier (DOI)
Archival Resource Key (ARK)
Grouping This image is part of a group.
Image Type
recorded image
Image Mode
differential interference contrast microscopy
time lapse microscopy
Chromophore-assisted laser inactivation
Parameters Imaged
optical path length gradient
Source of Contrast
boundaries between regions with different refractive index
Visualization Methods
Processing History
unprocessed raw data
Data Qualifiers
raw, unprocessed data
Sample Preparation
living tissue
Relation To Intact Cell
dispersed cells in vitro
Spatial Axis Image Size Pixel Size
X 407px ——
Y 430px ——
Time 3.2 seconds 100