Provider: ingentaconnect
Database: ingentaconnect
Content: application/x-research-info-systems
TY - ABST
AU - Gao, Yi
AU - Zhong, Zhenming
AU - Geng, Lei M.
TI - Calibration of Probe Volume in Fluorescence Correlation Spectroscopy
JO - Applied Spectroscopy
PY - 2007-09-01T00:00:00///
VL - 61
IS - 9
SP - 956
EP - 962
KW - FCS
KW - FLUORESCENCE CORRELATION SPECTROSCOPY
KW - PROBE VOLUME
KW - DIFFUSION
KW - CONFOCAL MICROSCOPY
KW - NONLINEAR LEAST SQUARES
KW - χ
KW - 2 SURFACE
N2 - In fluorescence correlation spectroscopy (FCS), an accurate evaluation of the probe volume is the basis of correct interpretation of experimental data and solution of an appropriate diffusion model. Poor fitting convergence has been a problem in the determination of the dimensional
parameters, the beam radius, ω, and the distance along the optical axis of the probe volume, *l*. In this work, the instability of fitting during the calibration process is investigated by examining the χ^{2} surfaces. We demonstrate that the minimum of χ^{2}
in the ω dimension is well defined for both converging and diverging data. The difficulty of fitting comes from the *l* dimension. The uncertainty in *l* could be significantly larger than that in ω, as determined by F-statistics. A modified calibration process is recommended
based on examining two data treatment methods, combining several short data sets into a single long run and averaging the correlation functions of several short data sets. It is found that by using the mean of several converging correlation functions from short data sets instead of a long
time correlation, more stable and consistent dimensional parameters are extracted to define the probe volume.
UR - http://www.ingentaconnect.com/content/sas/sas/2007/00000061/00000009/art00013
M3 - doi:10.1366/000370207781745883
UR - http://dx.doi.org/10.1366/000370207781745883
ER -