GENTAUR

Tel: +32 16 58 90 45

Fax: + 32 16 50 90 45

 info@genprice.com

Av. de l'Armée 68 • B-1040 BRUSSELS • BELGIUM

GENTAUR FRANCE

Tel: 01 43 25 01 50

9, Rue Lagrange • 75005 PARIS • FRANCE

Manual Magnetic Levitation Stirrers

The tumbling action of a VP 719F tumble stir disc in a glass
vial is illustrated in the 3 photos on the left. As the magnetic
cylinder spins the disc aligns it's magnetic poles to the cylinders
and tumbles vertically. The disc can reach speeds up to
500 RPM thus creating significant movement of the liquid in
the vials or wells.

Manual Magnetic Tumble Stirrer (patent pending) provides an economical way to re-suspend or mix compounds in microplates.
It is operated by hand using a simple slide mechanism to move our unique magnetic field under the microplates. It
also features a compact, chemical resistant ABS plastic body.

Alligator Magnetic Tumble Stirrer is a motorized stirrer. All of the motor and control used in the Alligator Tumble Stirrer are
rated for continuous rugged usage and are maintenance free. This model is capable of spinning the stir devices at speeds up to
500 RPM. The high speed tumbling action is great for many applications especially if you want to stir the contents of deep well
microplates. The ability to turn the stirrers over 500 RPM in the same direction, creates significant fluid movement. This fluid
movement and the physical interaction with the stir devices is ideal for resuspending
dried extracts, mixing viscous reagents and keeping organisms or
beads in suspension in deep well microplates.

Alligator Deck top Magnetic Tumble Stirrer is also a motorized stirrer. This Stirrer, with their 500 RPM speed, is ideal for
mixing in 96 deep well microplates or racks of glass vials containing chemical libraries. This Alligator Deck TopTumble Stirrer
fits comfortably on the deck of a Tecan Genesis robotic workstations and can be used to re-suspend libraries of stored compounds prior to sampling.

The Super Tumble Stirrer was built to stir heated reactions at great distance
from the stir deck. This ability allows for the use of thick aluminum reaction
blocks while maintaining the power to mix viscous solutions. We built the
strongest and largest permanent magnet imaginable and then coupled it to
our rotary motor stirring assembly. The result is a Super Tumble Stirrer
that will stir the most viscous reactions .
The deck is insulated against heat up to 180°C and a cooling fan keeps the
motor within operating specifications.

This is the smallest of our Rotary Magnetic Tumble Stirrers. It is powered by a variable speed DC motor on a 5 foot long flexible
drive shaft (longer or shorter drive shafts are available). This flexible drive model was designed to produce the smallest
footprint possible (18.8 cm long, 11.0 cm deep and 4.5 cm tall). A small footprint is a key feature for placing it on the deck of a
workstation where space is at a premium. The flexible drive shaft allows us to place the bulky motor and control systems at a
distance and also allows the Mini Tumble Stirrer to be moved about on the deck with ease. It's profile is only 4.5 cm high so it
can be accommodated by the "z" limitations of most robotic pipetting work stations. It can also be mounted under the deck of
certain robotic work stations. Its top speed is 500 RPM and it can fit on the deck of most workstations.

The Magnetic Levitation Stirrers (patent pending) were designed to stir the tall narrow columns of deep well 96 and the new
Whatman Polyfiltronics deep well 384 microplates. As scientists have sought to increase throughput of many processes they
have turned to miniaturization and deep well microplates as a solution. However one of the problems of using deep well microplates is being able to adequately mix the well contents or to re -suspend particles in these tall narrow wells. Another problem was that of getting enough oxygen exchange through the relatively small surface area of the deep well. We invented Magnetic Levitation Stirring as an efficient and inexpensive method to aerate and mix the contents of deep well microplates. We have done this by simply raising and lowering stainless steel balls in all the wells by using a very strong horizontal magnetic field.

This method produces a very vigorous stirring action which stimulates growth of microorganisms, mixes with ease two
or more liquids, and keeps particulates in suspension. Furthermore, if the media level in the wells is adjusted so the stir balls
pass through the meniscus, aeration of a microbial culture is increased and results in greater microbial yield as well as DNA
and protein production.

The gold standard for optimal bacterial growth is aeration using a shake flask on an orbital shaker. Unfortunately deep well
blocks (96 or 384) are not aerated like the flasks are on the orbital shaker and the growth fades when the oxygen in the media is depleted. One of our customers compared E. coli growth using Levitation Stirring in 96 deep well blocks and a shake flask on
an orbital shaker the results below demonstrated comparable growth curves between the two culture conditions. Thus it possible to obtain maximal DNA or protein yields in miniaturized culture conditions.
Scientists can apply this unique methodology to many different areas that require mixing of liquids or suspending particulates in the tall narrow wells of deep well microplates.