| Popis: |
We have developed a model-based, parallel procedure to estimate fluorescence lifetimes. Multiple frequencies are present in the excitation signal. Modeling the entire fluorescence and measurement process produces an analytical ratio of polynomials in the lifetime variable τ. A non-linear model-fitting procedure is then used to estimate τ. We have analyzed this model-based approach by simulating a 10 μM fluorescein solution (τ = 4 ns) and all relevant noise sources. We have used real LED data to drive the simulation. Using 240 μs of data, we estimate τ = 3.99 ns. Preliminary experiments on real fluorescent images taken from fluorescein solutions (measured τ = 4.1 ns), green plastic test slides (measured τ = 3.0 ns), and GFP in U2OS (osteosarcoma) cells (measured τ = 2.1 ns) demonstrate that this model-based measurement technique works. |
