Multicycle Pulling: Pulling A Patch-Type Micropipette; Heat Settings; Pull Setting; Trip Point Micrometer - Sutter Instrument P-30 Operation Manual

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Open upper glass clamp and insert glass capillary into jaws. Close down clamp on capillary
until glass is gripped lightly so glass can still slide. Slide capillary down through filament to
the point where the lower glass clamp can be raised up to grip lower end of capillary..
Tighten upper clamp and raise lower clamp over capillary. As glass capillaries may have a
slight curve to them, take care when inserting the capillary into the lower jaws. Tighten
lower glass clamp. The setting of the trip point is an important determinant of the size and
shape that will be obtained and will be covered below. Close front door and press PULL.
The following sequence takes place: 1) Filament turns on and glass is heated to softening
point. 2) As glass softens, lower glass clamp and slide bar descent under the influence of
gravity until the trip flag interrupts the optical switch. 3) The optical switch deactivates the
heat and activates the pull solenoid for approximately one second to complete pull.
Remove lower and upper pipettes.
4.4 Multicycle Pulling: Pulling a Patch 4.4 4.4 4.4 Multicycle Pulling: Pulling a Patch Multicycle Pulling: Pulling a Patch- - - - Type Micropipette Multicycle Pulling: Pulling a Patch
Patch type pipettes are characteristically stubby with a large taper angle and relatively large
tips (> 1 micron). To construct this type of pipette, it is desirable to process the glass in
multiple heating cycles. The P-30 can be used for two-step pipette fabrication with the use of
the dual heat settings and the supplied Patch Block. The first of the two steps draws the
glass out without separating. The glass tube must then be manually repositioned so that the
drawn-out portion is again centered within the heating element. The second step then draws
the glass out until it separates to form a pipette.
4.4.1 4.4.1

4.4.1 Heat Settings

4.4.1 Heat Settings Heat Settings Heat Settings
HEAT 1 is used for the first step, and is generally set at a fairly high level (e.g. 750 for 3mm
platinum filament or 970 for nichrome filament). HEAT 2 is used for the second step, after
the glass has already been pulled once. HEAT 2 will normally be less than HEAT 1, and is
more critical than HEAT 1. The exact value for your particular application will have to be
determined on a trail and error basis.
4.4.2 4.4.2 4.4.2 Pull Settin 4.4.2 Pull Settin Pull Setting g g g Pull Settin
Pull is normally set to zero for patch pipettes because the weight of the sliding components
provides the force that draws out the glass. If you desire, the solenoid plunger may be
disconnected from the slide assembly by loosening the set screw that attaches the cable to the
slide flag holder. This will decrease the weight by about 20%.
4.4.3 4.4.3 Trip Point 4.4.3 4.4.3

Trip Point Micrometer

Trip Point Trip Point icrometer icrometer icrometer
The micrometer should be advanced so that the flag does not interrupt the optical switch
until the second step is complete. Because the solenoid is generally not used in forming
patch pipettes, the trip point system serves primarily as a means of turning off the heat.
While it is easy to reposition the trip point for each step, it is generally more convenient to
use the RESET button to turn the heat off after the first step. Thus, the optical switch will
normally be placed so that the flag passes through the switch in the second step. This will
cause the heat to turn off automatically at the end of the second step.
P-30 MICROPIPETTE PULLER OPERATION MANUAL – REV. 3.10 (20100120)
Type Micropipette Type Micropipette Type Micropipette