QUB trace files from video

QUB trace files are ASCII files with the extension .txt. They are usually found in the main/video_processing/intensities/traces_QUB or main/traces_processing/traces_QUB analysis folder.

Table of contents

  1. Description
  2. File name
  3. Structure
  4. Compatibility
  5. References

Description

These trace files are written in an ASCII format importable in the software QUB [1]. The files contains intensity-time traces of a specific FRET pair, each molecule saved in individual files when integrated from a single molecule video (SMV) or all molecules saved in one file when exported after trace processing.

They are created in the /video_processing/intensities/traces_QUB analysis sub-folder after creating and exporting QUB traces in panel Intensity integration of module Video processing, or in or /traces_processing/traces_QUB if exported from panel Sample managementof module Trace processing.

File name

The file is named by the user during the export process.

By default, the file is named after the video file loaded in Video processing or the project file in Trace processing from which data are exported, and is appended with the extension:

  • _all[N]FRET[D]to[A]_QUB when exported from module Trace processing, where [N] is the number of single molecules, and where [D] and [A] are the channel indexes where donor and acceptor fluorescence are specifically detected
  • _mol[n]of[N]FRET[D]to[A]_QUB when exported from module Video processing and where [n] is the exported molecule index

Structure

FRET pair-specific intensity-time traces are organized column-wise with donor intensities being written in odd-indexed columns and acceptor in even-indexed columns.

9.193820e+03	-6.026230e+01	
8.319470e+03	1.600877e+02	
8.428510e+03	5.383770e+01	
9.067810e+03	-2.038123e+02

For consistency, intensity-time traces exported from module Video processing or Trace processing are always given as the sum of the brightest pixel intensities per video frame, regardless the units defined in Pixel intensity units or Intensity units respectively.

Compatibility

QUB trace files can be imported in external software QUB [1] and in MASH’s module Trace processing by adjusting the Import options to the actual file structure.

References

  1. C. Nicolai, F. Sachs, Solving Ion Channel Kinetics with the QuB Software, Biophys. Rev. and Letters 2013, DOI: 10.1142/S1793048013300053