Micropipettes are hollow glass needles with tip openings ranging from less than 1 μm up to 75 μm. Based on the size of the inner diameter of the micropipettes, they can be used for applications such as patch clamping, microinjection, and cell transfer. In the state-of-the-art fabrication of micropipettes, a skilled individual is able to produce about 2 − 4 micropipettes per minute. Many labs, which utilize hundreds of pipettes on a weekly basis, would benefit from the increased speed, accuracy, and repeatability of an automated fabrication apparatus. We have designed, built, and tested a working prototype of a fully automated fused silica micropipette puller. Our device pulls pipettes from a continuous spool of capillary glass, which leads to minimized setup time for the operator and the ability to produce 6 micropipettes per minute. Micropipettes were pulled with average lengths ranging from 6–20 mm and average tip diameters ranging from 18–175 μm. Standard deviations for length and diameter were calculated to range from 0.24-2.9 mm and 3.5–12 μm, respectively. Through measurements of the pulled pipettes, a trend has been determined which shows higher pulling velocity increases tip length and decreases tip diameter. A new model for heat transfer and geometrical analysis for the heating and cooling of the pipettes has been developed and matches closely to this experimental data. This can be used to predict pipette geometry.

References

References
1.
Brown
,
K. T.
, and
Flaming
,
D. G.
, 1992,
Advanced Micropipette Techniques for Cell Physiology
,
Wiley
,
Chichester, West Sussex
, 1986.
2.
Pak
,
K. W.
,
Umberto
,
U.
, and
Chih-Ming
,
H.
, 2004,
“Fabrication Process of Microsurgical Tools for Single-Cell Trapping and Intracytoplasmic Injection,”
J. Microelectromechan. Syst.
,
13
(
6
), pp.
940
946
.
3.
Hoffmann
,
P.
,
Dutoit
,
B.
, and
Salath
,
R.
,
“Comparison of Mechanically Drawn and Protection Layer Chemically Etched Optical Fiber Tips,”
Ultramicroscopy
,
61
(
1
), pp.
165
170
.
4.
Flaming
,
D.
,
“Method and Apparatus for Forming a Micropipette with Uniform Application of Heat,”
U. S. Patent US 4 921,
522
(1990).
5.
Sutter Instrument Company (Internet) (updated 2009 August 4; cited 2010 July 1) P-2000 — Quartz Micropipette Puller
, available from: http://www.sutter.com/products/product_sheets/p2000.htmlhttp://www.sutter.com/products/product_sheets/p2000.html
6.
MicroData Instruments, Inc. (Internet), (updated 2009 February 9, cited 2010 July 1) PMP-102Q Quartz Glass Micropipette Puller
, available from: http://www.microdatamdi.com/pmp-102q.htmhttp://www.microdatamdi.com/pmp-102q.htm
8.
Accuratus (Internet), (updated 2002, cited 2011 February 14) Fused Silica
, available from: http://accuratus.com/fused.htmlhttp://accuratus.com/fused.html
9.
Churchill
,
S. W.
, and
Bernstein
,
J. M.
, 1977,
J. Heat Transfer
,
99
, pp.
300
.
10.
Churchill
,
S.W.
, and
Chu
,
H. H. S.
, 1975,
Int. J. Heat Mass Transfer
,
18
, pp.
1049
.
11.
Sutter Instruments, 2010, P-2000 Micropipette Puller Operation Manual-Rev 2.2.
12.
Budynas
,
R. G.
, and
Nisbett
,
J. K.
, 2008,
Shigley’s Mechanical Engineering Design
,
McGraw Hill
,
New York
, pp.
402
, Chap. 8.
You do not currently have access to this content.