Dual-doped thermographic phosphor particles as surrogates for GFP-labelled cells in tests of cytometric neurocatheters...

We investigated the laser-induced fluorescence of particles of a compound thermographic phosphor La2O2S:Eu (1%) and Gd2O2S:Eu (1%), to see if they can serve as a surrogate for cells transfected with the green fluorescent protein, in tests of neurocatheters used for intraparenchymal cell delivery. At an excitation wavelength of 337 nm and a concentration of ≈ 2x106 particles ml-1, the resulting slurries produced fluorescence intensities at 625 nm that were within a factor of two of those produced by similar number densities of relevant cells, thus suggesting the utility of this approach.