June 1, 2005 (Vol. 25, No. 11)
Lab Workhorses Optimize Cultivation of Biological Samples
Preventing contamination using thermal decontamination routines and the upcoming use of oxygen control could be seen as trends in incubation, according to Rainer Zagst, product marketing manager of Kendro Laboratory Products (www. kendro.spx.com). The biggest problem in incubation is the contamination of cell cultures with “unwanted guests,” he explains.
Bacteria, fungi, and mycoplasma prosper in the humid heat of the incubator just as well as the cells themselves. These “guests” are parasites in every cell cultivation laboratory. They use the medium’s nutrients and overgrow the cells within no time at all. “It is unfortunate that their existence is often only evident once it is too late,” Zagst continues.
“It is therefore important to treat the incubator and the cells in a way such that contamination is virtually eliminated. It only takes a few simple steps to achieve more satisfaction when dealing with cell cultures and more success with the experiment.”
Kendro offers the Heraeus CO2 Incubator BBD 6220, designed for a contamination protection for optimum reproducibility of results in microbiological laboratories and for in vitro fertilization as well as cancer research or tissue engineering, according to Zagst.
The interior of the BBD 6220 is disinfected with a fully automatic 180C hot-air disinfection system that eliminates time-consuming manual removal and replacement of internal fittings and minimizes the risk of contamination. Each phase of disinfection is indicated on a status display. After disinfection, the incubator changes over automatically to closed-loop control with the preset incubation conditions.
The BBD 6220 provides permanent sterilization of the complete vapor generation system, according to Zagst. The external arrangement of the water reservoir allows its continuous thermal decontamination by cyclically heating it up to 80C.
This method, known as tyndallization or fractional sterilization, is used to kill microorganisms, particularly spores. The humidifying vapor produced is briefly exposed to high temperatures before it enters the internal chamber and is thus effectively sterilized once more. Contamination is prevented by the humidification system, Zagst says.
The active humidification system of the BBD allows humidity regulation in the range from 6095% rH. The humidity content is continuously measured with a capacitive measuring probe and regulated by a finely injected addition of water vapor.
Researchers have a choice: high humidity for optimum cell culture, particularly when using a small amount of medium, or lower humidity for the safe functioning of stirrers, shakers, or roller systems.
Joining New Brunswick Scientific’s (www.nbsc.com) line of direct heat CO2 incubators, the Innova CO-14 micro CO2 incubator is specifically designed for in vitro fertilization needs as well as cell culturing studies that must maintain sample separation, according to Mark Kunkel, product manager.
Innova CO-14 enables researchers to keep their cell culture work at their workspace, while providing the features of the direct-heat CO2 incubator line, such as oxygen control, seamless/fanless chambers, and intuitive controls.
“The incubator’s 0.5-cubic-foot, direct-heat chamber provides a great deal of personal work space in a unit less than 12 inches tall,” Kunkel says. “The Innova CO-14’s diminutive size and lightweight design allow it to be placed singly or stacked, just about anywhere space is available.”
UVP’s (www.uvp.com) UV Sterilizing Incubator is designed to provide precise temperature control and uniformity throughout the chamber for incubation of biological assays, fungal, bacterial cultures, eggs and other biological samples.
Benefits include microprocessor-controlled temperature with uniformity throughout the chamber, the ability to sterilize the chamber between experiments with 254-nm shortwave UV, the inclusion of two ventilated shelves, and a small laboratory footprint, according to Alex Waluszko, vp of marketing and sales.
Union Scientific (www.unionscientific.com) claims that its VibraTornado is the world’s first electromagnetic vortex generator. One-knob operation can create a gentle or powerful vortex in any diameter or shape, according to Mitchell Friedman, president of the company.
The VibraTornado will generate a mixing vortex in almost any kind of labware. It can mix 192 2.5-mL or similar tubes in racks simultaneously; four deep-well plates, each containing 96 or 384 deep wells, round or square; or any combination of shallow well plates in two stacks 3.75 inches high with 96, 384, or even 1,536 wells each.
There are various factors to consider when creating a vortex in a test tube, according to Friedman. Putting something into the liquid to create the vortex may be undesirable or difficult. In addition, the type of vortex created must allow for mixing of the substance in the test tube.
The two limits that must be overcome in forming a vortex are the capillary limit to allow the liquid to move up and a large enough radius for a boundary layer to develop, Friedman explains.
Orbital motion can be created mechanically, which is especially helpful in causing a vortex in a small tube, such as those used in arrays or microplates, Friedman adds. The VibraTornado is designed to overcome the capillary limit and form a mixing vortex by orbiting small test tubes or microplates.
Barnstead Thermolyne (www. barnsteadthermolyne.com) offers the Labquake shaker for thorough mixing of blood samples, preparation of homogeneous dispersions, dialysis under agitation, and liquid-liquid extractions.
It is available in clip-bar, double-deck, or combination models. Clip-bar models feature continuous rotation at 8 rpm or oscillating action at 2270 reversals per minute, while double-deck models feature oscillating action at 2270 reversals per minute, depending on the angle.
Rich Manzari, product manager at New Brunswick Scientific, reports that the Innova 40 and 40R incubated/refrigerated benchtop shakers and the Innova 43 and 43R floorstanding incubated shakers will soon be available. These models complement the Innova 44 and 44R Stacking incubated shakers.
A key feature of the new Innova series is intuitive programming, which enables multiple parameter changes, including temperature, speed, photosynthetic lights, and UV light decontamination.
There are four programs of 15 steps each on a large display that is visible throughout the laboratory. All are easily changed on a timed basis, making them well suited for heat inductions or temperature reductions to slow growth, eliminating unnecessary trips back to the lab, according to Manzari.
“Researchers can program the system automatically to make changes in temperature, speed, and other parameters, instead of coming in on weekends to change it.”
AutoGen’s (www.autogen.com) new shaking incubator, the AutoIncubator 96, can incubate and shake up to 16 of AutoGen’s tube units to prepare 96 samples at a time, says Jill Podzka, sales specialist.
“This new system is appropriate for bacterial cultures and enzyme reactions, such as Proteinase K digestion. Now researchers can further simplify their pre-DNA extraction process by preparing their samples with the AutoIncubator 96 and then placing the company’s 6-hole tube units directly onto one of its medium throughput DNA extraction systems.”
The iEMS Incubator/Shaker from Thermo Electron (www. thermo.com) is a high-performance 96-well plate incubator and orbital shaker designed for demanding microplate EIA assays requiring temperatures of up to 40C. It can handle up to nine 96-well plates and fit into a small bench space in medium-sized laboratories.
A high-performance microplate incubator and orbital shaker, the iEMS Incubator/Shaker offers temperature control and orbital shaking capabilities that help to reduce incubation times. Features include temperature uniformity across the plate, efficient orbital shaking, sensitivity and specificity for EIA assays, and capacity up to nine microplates.
The iEMS Incubator/Shaker uses an individual thermal microplate holder designed for ease of use and uniform heating of each microplate. Temperature variation is less than 0.3C across the microplate. To eliminate temperature gradients and edge effects, microplates are evenly heated from all sides to ensure assay reproducibility.
A powerful variable-speed orbital shaker facilitates effective mixing. Featuring an orbit of 0.1 mm and speeds from 400 to 1,400, in 250 rpm increments, the shaker motion ensures efficient mixing of even very viscous liquids.
In today’s laboratory, small is beautiful, according to Steve Mitchell, president of Appropriate Technical Resources (ATR; www. atrbiotech. com). The company has taken its Infors Multitron line of shaking incubators and optimized it for specific applications.
The products have optional refrigeration, CO2, and humidity controls for small sample sizes in high throughput applications. Other features include a front-loading pullout platform, stainless steel interior panels, a panoramic front window, an inspection light, and a patented drive system for uniform motion and quiet operation without vibration, notes Mitchell.
ATR also offers the Ecotron personal shaking incubator. This new addition takes the equipment out of the common area and puts it directly on the benchtop, continues Mitchell.
“Sample sizes are smaller, though sample volumes are increasing. That’s the nature of high throughput screening.”