Membrane formation

  
Bilayer lipid membranes are widely used as a model of biological membranes. They are used also as a support in biosensors based on biological membrane receptors.

 Membrane capacitance is one of characteristic parameters of bilayer lipid membranes. They have high capacitance, 0.3-1.3 uF/cm2, because their thickness is very low, a few nanometers.

 Planar lipid bilayer can be formed by Mueller-Rudin-Tien-Wescott method. This method is based on the self-assembling phenomenon. This process can be controlled by measuring of membrane capacitance. The program "Membrane formation" is used to recording of capacitance as a time function.

Application of membrane capacitance measurements

  • observation of the membrane formation process
  • estimation and investigation of membrane stability
  • investigation of membrane formation mechanism
  • measurement of membrane thickness
  • studies of membrane structure
  • studies of membrane transport processes
  • studies of photoeffects in membranes

    • Hardware

    The program controls the KSP measurement system with following modules:

    CCONV-40 - capacitance-to-digital converter
    DAC-1201 - digital-to-analog convereter
    TIMER-49 - programmable timer

    Measurements are made in a four-electrode arrangement.

    Features of the program

  • Run, Stop, Pause, Continue commands
  • saving of data and printing of the report
  • writting of data as a text file for using in worksheets and graphic programs
  • selection 2- or 4-electrode system
  • setting up to 10 methods (sets of measurement parameters and experiment descriptions)
  • waiting for start of membrane formation
  • beep after start and breakdown of a membrane
  • readout of data directly from the graph
  • readout of curve slope directly from the graph
  • zoom of the graph


    •  Main window of the "Membrane formation" program.

    Used files

    BLMFORM.EXE - main program file
    BLMFORM.INI - configuration file
    BLMFORM.HLP - help file

     CCONV.DLL - driver for the capacitance-to-digital converter module
    DAC.DLL - driver for the digital-to-analog converter module
    TIMER.DLL - driver for the programmable timer module

     *.FRM - files with measurement data

     The files BLMFORM.EXE, BLMFORM.INI, BLMFORM.HLP are contained in the file BLMFORM.ZIP.
    The *.DLL files you must download separately.

    Selected papers
  • S. Kalinowski and Z. Figaszewski, A new system for bilayer lipid membrane capacitance measurements: method, apparatus and applications. Biochim. Biophys. Acta, 1112 (1992) 57-66.
  • S. Kalinowski and Z. Figaszewski, Uklad do pomiaru pojemnosci membran, Polish patent nr 161973, March 28, 1994.
  • S. Kalinowski and Z. Figaszewski, A four-electrode system for measurement of bilayer lipid membrane capacitance, Meas. Sci. Technol., 6 (1995) 1043-1049.


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