title: Cell Viability and DNA Denaturation Measurements by Two-Photon Fluorescence Excitation in CW Al:GaAs Diode Laser Optical Traps.
abstract: Cell viability and DNA denaturation are measured through two-photon fluorescence excitation using a single diode laser beam as the trapping and exciting source simultaneously. Two-photon fluorescence emission spectra are presented for CHO cells and T lymphocytes loaded with various fluorescent probes. This single beam method is demonstrated to be a safe tool to monitor the viability of optically trapped cells, even under intense 809 nm diode laser illumination (∼106 W/cm2). The dynamics of cellular necrosis is monitored by adding ethanol to the cell suspension during trapping. Thermal damage to heat-treated samples is assessed by recording shifts in the emission spectra from trapped cells loaded with the nucleic acid probe, acridine orange. © 1999 Society of Photo-Optical Instrumentation Engineers.
authors.forename: Z X
authors.initials: ZX
authors.lastname: Zhang
authors.forename: G J
authors.initials: GJ
authors.lastname: Sonek
authors.forename: X B
authors.initials: XB
authors.lastname: Wei
authors.forename: C
authors.initials: C
authors.lastname: Sun
authors.forename: M W
authors.initials: MW
authors.lastname: Berns
authors.forename: B J
authors.initials: BJ
authors.lastname: Tromberg