Shown below is a screen shot of the pipette clog test monitor where the pipette was found to be unsuitable for autopatching. This is very typical of a pipette where debris from the Ag/ AgCl electrode wire fall off to the tip during program operation. Such variations should not be seen when the pipette has been kept in the saline solution outside of the brain. Steps that can be taken to prevent internally clogged pipettes include: Proper chloriding of Ag/ AgCl wires: While have the silver wire in the pipette holder be chloride for stable recording, too much Ag/AgCl is bad. Ensure that chloriding is done to the minimum extent possible to ensure stable recordings. It is a good idea to take the electrode wire in the pipette holder: a kimwipe soaked in 70% ethanol and clean the electrode wire. Change the filter on the pipette filler. Always ensure the pipette solution is filtered with a 0.2 micrometer filter. Change the filter periodically. Microfil storage: Ensure that the microfil is stored in a 70% ethanol solution when not in use. If multiple pipettes show signs of getting clogged internally, it is important to ensure that the microfilm is cleaned out again with a kimwipe soaked in 70% ethanol. Noise in resistance measurement: If there is noise in the resistance measurement and the variation is over 0.02 and the average resistance remains the same, it is possible that the pipette has not been positioned properly at the start of the program. Visualizing the current traces in clampex can be a good way to debug this. If improperly positioned the current traces during pipette clog test check will look as follows:
Shown below is a screen shot of the pipette clog test monitor where the pipette was found to be unsuitable for autopatching. This is very typical of a pipette where debris from the Ag/ AgCl electrode wire fall off to the tip during program operation. Such variations should not be seen when the pipette has been kept in the saline solution outside of the brain. Steps that can be taken to prevent internally clogged pipettes include: Proper chloriding of Ag/ AgCl wires: While have the silver wire in the pipette holder be chloride for stable recording, too much Ag/AgCl is bad. Ensure that chloriding is done to the minimum extent possible to ensure stable recordings. the electrode wire in the pipette holder: It is a good idea to take a kimwipe soaked in 70% ethanol and clean the electrode wire. Change the filter on the pipette filler. Always ensure the pipette solution is filtered with a 0.2 micrometer filter. Change the filter periodically. Microfil storage: Ensure that the microfil is stored in a 70% ethanol solution when not in use. If multiple pipettes show signs of getting clogged internally, it is important to ensure that the microfilm is cleaned out again with a kimwipe soaked in 70% ethanol. Noise in resistance measurement: If there is noise in the resistance measurement and the variation is over 0.02 and the average resistance remains the same, it is possible that the pipette has not been positioned properly at the start of the program. Visualizing the current traces in clampex can be a good way to debug this. If improperly positioned the current traces during pipette clog test check will look as follows:
AutoPatch1506_User_Manual_ver1.0.docx