A novel method for detection of virus-infected cells through moving optical gradient fields using adenovirus as a model system.
BACKGROUND
Most methods for cellular analysis require labeling with specific antibodies or dyes and are often destructive. We have developed a technology called Optophoresis trade mark, which measures cell physiology based on the cell's motion in a near-infrared optical gradient. This technique does not require labels, is nondestructive, and involves minimal sample processing.


METHODS
We have used Optophoresis to interrogate nonproductive and productive adenovirus-infected cell lines. Using an adenoviral vector containing green fluorescent protein (GFP) as a secondary assay, we show that viral infection can be monitored with Optophoresis.


RESULTS
In HeLa cells, adenovirus infection after 24 h caused a 12% to 17% increase in optophoretic motility of the cells. In 293 cells, adenovirus infection resulted in a 40% increase in the optophoretic motility. The P values obtained were 4.5 x 10(-11) between noninfected and infected HeLa cells, and 2.1 x 10(-13) between noninfected and infected 293 cells. Cells infected with adenovirus lacking the GFP reporter gene gave similar shifts. In a time course, we observed an optophoretic shift after 4 h of infection, well before GFP expression.


CONCLUSIONS
Optophoresis provides nondestructive, label-free analysis of viral infection. Detection is independent of reporter gene expression and can be observed early in the infection process.
Soo Hoo
William
W
Genoptix, Inc., San Diego, California 92121, USA.
Wang
Mark
M
Kohrumel
Joshua R
JR
Hall
Jeff
J
D000256:Adenoviridae / Q000302:isolation & purification* / Q000502:physiology; D002460:Cell Line; D002477:Cells / Q000821:virology*; D019937:Diagnostic Techniques and Procedures / Q000295:instrumentation*; D005470:Fluorometry; D006367:HeLa Cells; D006801:Humans; D007259:Infrared Rays; D007834:Lasers; D009038:Motion; D055095:Optics and Photonics; D010957:Plasmids / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013997:Time Factors
D011993:Recombinant Fusion Proteins