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Uniform
suspension of cell cultures and microcarrier beads is achieved by gentle stirring action
which aids attachment and promotes circulation of the medium around the cells to encourage
a high growth rate. Special SOFTSTART design ensures controlled
acceleration of the stirrer rod to the selected speed, thus avoiding excessive turbulence
within the medium on start-up, and eliminating cell damage. SOFTSTART also controls
deceleration on switch-off.
As well as continuous stirring fully controllable up to 80 rpm, the
stirrers incorporate fully variable interval stirring. You can choose "on" times
between 6 seconds and 5 minutes, and "off" times between 2 minutes and 2 hours.
Automatic cycling improves cell yields in certain conditions, particularly during the
attachment stage.
The
unique stirring action of the TechneŽ stirrers is derived from a design which makes use of
both Einstein's and J.J.Thompson's observations that conditions can be created in a
stirred fluid whereby primary and secondary flow patterns produce not only expected
horizontal circulation but also vertical circulation - upwards in the middle and downwards
at the sides - to create a gentle controlled spiraling movement within the culture
medium. This pattern is generated by a specially formed stirring
rod which moves slowly through the culture medium in a vessel shaped to correspond with
the profile of the rod. Flow is greatly assisted by the lack of obstruction to the
vertical flow line. In contrast, conventional stirrers create uncontrolled conditions in
the stirred liquid; in particular, there is a point of stagnation immediately below the
axis of rotation. Stirrers of this type are inherently incapable of producing the
secondary flow pattern of the TechneŽ stirrers; instead they create turbulent conditions
which damage cells. The Stirrers are virtually heatless and therefore particularly
suitable for the use in an incubator, unlike many magnetic stirrers which generate
excessive heat and cannot satisfactorily be used in an incubator.
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A further advantage of the TechneŽ stirrers is that the culture
vessels can be sealed for use with pathogenic materials. The stirrer rod design eliminates
rotating bearings within the culture vessels, avoiding the difficulties arising from
attempts to clean and autoclave conventional vessels. Even a bearing well above the
surface of the liquid in the conventional design suffers from contamination and gives rise
to trouble, presumably as a result of the Weisenburg effect.
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Five stirrer sizes are available.
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Seven culture vessels, 125-5000 ml
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Calibrated speed control and interval stirring.
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All solid state controls
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Polished stainless steel housing
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Strong, rugged and lightweight - built for years of use
A TechneŽ Stirrer System comprises a
polished stainless steel platform which houses the motor and controls; Culture vessels are
located by pips. The stirrer rods are activated by magnetic coupling from rotating magnets
under the platform, driven by a long-life motor with ironless rotor. The design of the
motor and its associated circuits ensure that it generates no heat.
All models in the range are suitable
for incubator/warm room use; the MCS-104L and MCS-101L will take a specially designed
water bath. The MCS platform is provided with a fuse and on/off switch. Electrical supply
to the platform is via a detachable cable making it easy to use the stirrer in an
incubator fitted with a cable port. TechneŽ 's MCS range of stirrers are designed to comply
with all important RF interface and electrical safety regulations.
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Ordering Information