Electrophysiological Methods: Physical Techniques in by William L. Nastuk

By William L. Nastuk

Show description

Read or Download Electrophysiological Methods: Physical Techniques in Biological Research (Volume 5) PDF

Similar botany books

Handbook to the Construction and Use of Insect Collection and Rearing Devices: A guide for teachers with suggested classroom applications

Bugs are nice school room learn organisms. they're effortless to gather and lift and feature a desirable array of lifestyles histories. simply because they're small and feature large reproductive means ecological experiences of dispersion, predation, parasitism and replica will be studied in compressed timeframes and small components relative to related stories of bigger organisms.

Extra info for Electrophysiological Methods: Physical Techniques in Biological Research (Volume 5)

Sample text

Pipettes made from such stock tubing are strong enough to penetrate a centimeter or more of central nervous system tissue without breaking. Where m a x i m u m strength is not required, a thinner wall yields a pipette with larger lumen and hence lower resistance. A di­ ameter of 3-4 m m is about the m a x i m u m which has been used with single stage pullers. Where a still larger stem is required, a two-stage pull is recom­ mended. G o o d reproducibility in drawing pipettes requires a preselection of stock tubing to an O .

A fivefold increase in final force appears to make only a slight increase in tapered length and a slight de­ crease in final taper. d. PIPETTE T I P S T h e tips of micropipettes are often smaller than the w a v e length of visi­ ble light. Consequently when an ordinary light microscope is used to o b ­ serve such tips, diffraction lines appear o n either side of the image where 48 κ . FRANK AND Μ. C. BECKER 1000 100 1000 10000 L E N G T H {μ) F I G . 10. Effect of varying length of heater coil, a—heater coil IJ^ turns, heater current 2 4 .

A s 52 κ . FRANK AND Μ. C. 100 LiJ 10 h 100 1000 10000 LENGTH F I G . 14. Effect of varying final force alone. 5 kg. 33 kg for both a and b. Insert shows force-displacement curves with starting and separation points indicated by arrows. 4 5 LENGTH 6 (μ) F I G . 15. Effect of pipette length on final tip taper. Total length of pipettes: a— 8 mm; b—16 mm; c—21 mm. 2 amp. can be seen, there is a close fit between inner and outer pipette o v e r a dis­ tance of 500μ. A s a result, the resistance of the outer pipette becomes very high at maximum protrusion even for a fairly coarse outer tip.

Download PDF sample

Rated 4.05 of 5 – based on 15 votes