The patch-clamp Seal Test protocol has been implemented to make easier patch-clamp gigohm seal whole-cell recordings, in particular reading out pipette resistance (Rpipette) when the electrode is in the bath, seal resistance (Rseal) when forming the seal, and series resistance (Rs), cell input resistance (Rm) and the steady state DC current (Idc) when going/gone whole-cell.

With WinLTP in the Normal Mode, to go to Seal Test, click on the "SealTest AD0" or "AD1" button.  In order for these SealTest buttons to appear, AD0 and/or AD1 datatype must be in "pA" (set by the File->Edit Protocol File dialog box).

For Electrode in Bath, put the patch electrode or pipette in the bath and record the electrode or pipette resistance (Rpipette) by clicking the Electrode in Bath "Start (F5)" button (or by pressing F5).  Set the appropriate pulse amplitude in the Pulse Amp edit field.

For Form Seal, once the electrode is on the cell surface, click the "Start - Low Pulse Amp (F6)" button (or press F6) to output the low pulse amplitude pulse to approximately measure the seal resistance, Rseal.  Once the seal is coming into the Gohm range, click the "Start - High Pulse Amp (F7)" button (or press F7) to output the high pulse amplitude to accurately measure the seal resistance, Rseal.  Set the appropriate low and high pulse amplitudes in the neighboring pulse amplitude edit fields.

For more information see Chapter 6 in the on-line WinLTP Manual.

As shown in the above figure of Going Whole-Cell, after the gigaohm seal has been formed and you are ready to go whole cell, click the Go Whole Cell "Start (F8) " button (or press F8) to record the seal resistance (Rs, in Mohms), the input resistance (Rm, in Mohms) and the steady state DC current (Idc, in pA) (see the figure, bottom left).  Set the appropriate pulse amplitude in the Pulse Amp edit field.  Also when going whole cell, you can plot the Rs and Rm values and them the spreadsheet by checking the “Plot and Print Rs/Rm Values” checkbox, and you can save the Rs/Rm sweep files to disk by checking the “Save RsRm Sweeps to Disk” checkbox.  The test stimulation can be stopped by pressing the “Stop (F4)” button (or pressing F4).

Return to the Normal Mode Protocol by clicking "Return to Protocol" button.