Legacy raw data formats

The Beckman centrifuge generates raw data files that depend on the type of experimental run and the sensor. Files for a run are placed into a run specific directory. The file name is significant. The file names correspond to legacy DOS 8.3 format, generally in the form of 00001.RA1 or A00001.FI5. Each file is a single scan. The extensions to the filenames are:

  • RA - Radial Absorbance
  • IP - Interference
  • RI - Radial Intensity
  • FI - Fluorescence Intensity
  • WA - Wavelength Absorbance
  • WI - Wavelength Intensity

The file name extension's final character is a digit that represents the cell number of the run.

Fluorescence filenames are preceded with a capital letter, generally A through J, designating the channel of that scan.

Some data types can record up to three wavelengths in a run. This is done through multiple files, e.g:

  • 00001.RA1 -- First Wavelength
  • 00002.RA1 -- Second Wavelength
  • 00003.RA1 -- Third Wavelength
  • 00004.RA1 -- First Wavelength
  • 00005.RA1 -- Second Wavelength
  • 00006.RA1 -- Third Wavelength
  • etc

or if the run was made with two wavelengths:

  • 00001.RA1 -- First Wavelength
  • 00002.RA1 -- Second Wavelength
  • 00003.RA1 -- First Wavelength
  • 00004.RA1 -- Second Wavelength
  • etc

The only way to tell is to look at the 7th parameter in the meta data line of each file.

Internal file formats

The file format looks like:

water chm A BSA chm B
I 2 20.2 35000 0000164 1.1690E09 230 1
   5.8090  3.88350E+0002   9.72590E+0002
   5.8100  2.34391E+0003   2.13340E+0003
   5.8110  2.35336E+0003   2.10592E+0003
   5.8120  2.53739E+0003   2.20910E+0003

Description line

The first line is a description of the data. Fluorescence data does have some run information embedded here. For example:

10/3/2006 12:05:14 PM: Voltage: 2197 Gain: 4 Range: 4

Meta data Line

This line consists of eight fields:

  1. Scan sensor type. This is a single letter.
    • P interference
    • I intensity
    • R absorbance
    • W multi-wavelength
    • F fluorescence
  1. Cell number
  2. Temperature in degrees C
  3. RPM
  4. Seconds since the start of the run
  5. The centrifuge's calculated omega2t value
  6. Wavelength
    • For multi-wavelength data (*.WA? files), it is the the radial position of the scan
  7. The count of the number of readings made for each value

Data Lines

Each line consists of three fields:

  1. The radial position of the sensor. Generally this is between 5.7 and 7.2.
    • For *.WA? files, it is the wavelength of the reading
  2. The value of the reading
  3. The standard deviation of the reading
    • If the count (#8 above) is 1, the standard deviation will be zero
    • For .RI? files, this value appears to be that of a 2nd channel, but this needs to be validated
Last modified 11 years ago Last modified on Jul 19, 2009 1:05:02 PM