# I. Generate bleach corrected correlation functions using Fluctuation Analyzer 4G (FA)
The [FA](https://www.embl.de/~wachsmut/downloads.html) is a software for the interactive as well as automated processing of fluorescence correlation and cross-correlation spectroscopy (FCS and FCCS) data. Refer to the manual of FA and the original article [Wachsmuth et al. (2015)](http://europepmc.org/abstract/MED/25774713) for details.
The FA is a software for the interactive as well as automated processing of fluorescence correlation and cross-correlation spectroscopy (FCS and FCCS) data. Refer to the manual of FA and the original article [Wachsmuth et al. (2015)](http://europepmc.org/abstract/MED/25774713) for details. Download FA from http://www.fluctuations.de/ or https://www-ellenberg.embl.de/resources/data-analysis.
The installation may require LabView development libraries (free). Please download them from
http://www.ni.com/en-us/shop/labview/download.html Application area 'Develop Production Test Systems'. Follow the instructions. You will need to restart the computer several times. This will also install the .NET framework.
In this WiKi we provide a detailed explanation on which settings and parameters to use for the FCS-calibration protocol. At least the following 4 steps must be executed:
