Patch-Pipettes; Glass Capillaries - HEKA EPC 9 Manual

9. Patch-Pipettes

Glass Capillaries

Procedures for fabricating pipettes are presented in some detail in the paper by
Hamill et al. We will summarize the procedure and present some tips that we have
found helpful. The main steps in pipette fabrication are to form a smooth tip on the
pipette (to allow seals to be formed without damaging the cell membrane) and to
coat the pipette with a suitable insulating coating to reduce the background noise.
Pipettes can be made from many different types of glass. Our impression is that
different types of glass work better on different cell types. Glass capillaries are
available from soft (soda glass, flint glass) or hard glasses (borosilicate,
aluminosilicate). Some sources of glass pipettes:
Soft Glass (Supplier)
Non-heparinized hematocrit tubing
any scientific supplier
Drummond Microcaps
Drummond Scientific, Bloomall, PA, U.S.A.
Hard Glass (Supplier)
Kimax 51
Kimble Products, Vineland, NJ, U.S.A.
Boralec 100
Rochester Scientific, Rochester, NY, U.S.A.
Corning Sealing Glass (#7052, #7040)
Dow Corning, Midland, MI, U.S.A.
GCASS 150-4 (aluminum glass)
A-M Systems, Everett, WA, U.S.A.
Soft-glass pipettes have a lower melting point (800 ˚C vs. 1200 ˚C), are easily
polished, and can be pulled to have a resistance of 1-2 MΩ. They are often used for
whole-cell recording, where series resistance rather than noise is the limiting
criterion. The large dielectric relaxation in soft glass sometimes results in additional
capacitive-transient components that interfere with good capacitance compensation.
Patch-Pipettes EPC9 Manual
OD
1.3 mm
1.4 mm
OD
1.7 mm
1.7 mm
1.6 mm
1.5 mm
71