Can we use rapid lifetime determination for fast, fluorescence lifetime based, metabolic imaging? Precision and accuracy of double-exponential decay measurements with low total counts

Autor: José Paulo Domingues, António Miguel Morgado, Susana F. Silva
Rok vydání: 2019
Předmět:
Fluorescence-lifetime imaging microscopy
Biochemistry
01 natural sciences
Fluorescence Microscopy
Microscopy
Biochemical Simulations
Physics
0303 health sciences
Multidisciplinary
Applied Mathematics
Simulation and Modeling
Optical Imaging
Light Microscopy
Power (physics)
In Vivo Imaging
Optical Equipment
Physical Sciences
Metabolome
Engineering and Technology
Medicine
Algorithms
Research Article
Cell Physiology
Accuracy and precision
Imaging Techniques
Science
Equipment
Research and Analysis Methods
Noise (electronics)
Fluorescence
010309 optics
03 medical and health sciences
Fluorescence Imaging
0103 physical sciences
Humans
030304 developmental biology
Pixel
Lasers
Double exponential function
Biology and Life Sciences
Computational Biology
Cell Biology
Cell Metabolism
Computational physics
Microscopy
Fluorescence

Mathematics
AND gate
Zdroj: PLoS ONE, Vol 14, Iss 5, p e0216894 (2019)
PLoS ONE
ISSN: 1932-6203
DOI: 10.1371/journal.pone.0216894
Popis: Fluorescence lifetime imaging microscopy (FLIM) can assess cell's metabolism through the fluorescence of the co-enzymes NADH and FAD, which exhibit a double-exponential decay, with components related to free and protein-bound conditions. In vivo real time clinical imaging applications demand fast acquisition. As photodamage limits excitation power, this is best achieved using wide-field techniques, like time-gated FLIM, and algorithms that require few images to calculate the decay parameters. The rapid lifetime determination (RLD) algorithm requires only four images to analyze a double-exponential decay. Using computational simulations, we evaluated the accuracy and precision of RLD when measuring endogenous fluorescence lifetimes and metabolic free to protein-bound ratios, for total counts per pixel (TC) lower than 104. The simulations were based on a time-gated FLIM instrument, accounting for its instrument response function, gain and noise. While the optimal acquisition setting depends on the values being measured, the accuracy of the free to protein-bound ratio α2/α1 is stable for low gains and gate separations larger than 1000 ps, while its precision is almost constant for gate separations between 1500 and 2500 ps. For the gate separations and free to protein-bound ratios considered, the accuracy error can be as high as 30% and the precision error can reach 60%. Precision errors lower than 10% cannot be obtained. The best performance occurs for low camera gains and gate separations near 1800 ps. When considering the narrow physiological ranges for the free to protein-bound ratio, the precision errors can be confined to an interval between 10% and 20%. RLD is a valid option when for real time FLIM. The simulations and methodology presented here can be applied to any time-gated FLIM instrument and are useful to obtain the accuracy and precision limits for RLD in the demanding conditions of TC lower than 104.
Databáze: OpenAIRE