“I am very pleased with the performance of the Omni Bead Ruptor 24. It was one of the first items on my lab start-up list. The superior efficiency and uniform homogenization from sample to sample are well worth the investment.”
Jason C. O’Connor, Ph.D.
Department of Pharmacology
The University of Texas Health Science Center

“This machine is pretty amazing because it revolutionized the way we process plant tissue, especially difficult plant tissues.”
Phat Dang
USDA

• Is cross-contamination a concern in your lab?

• Have you ever lost valuable sample in your laboratory homogenizer probe?

• Are you tired of wasting time cleaning stainless steel homogenizer probes?

If you answered “yes” to any of these questions you should check out the Omni Tip™ Clear Plastic Homogenizer Probes. These probes are engineered from durable plastics and can process a wide variety of sample types.

The soft tissue Omni Tips are ideal for liquid homogenization, emulsifications and tissues such as liver and brain.

The hard tissue Omni Tips are ideal for kidney, heart, muscle, tumor, frozen and other similar tissue types.

Omni Tips are just as effective at homogenizing samples as their stainless steel counterparts, but they remove all of the hassle associated with stainless steel probes. Omni Tips are disposable, eliminating any risk of cross-contamination between samples during processing. However, Omni Tips can be reused if necessary. Their simple two-piece design makes them extremely easy to disassemble and clean. Furthermore, the clear outer tube of the Omni Tips prevents sample-loss because any sample that makes its way up into the tube is always visible.

Omni Tip plastic probes can be used to process sample volumes of 0.25mL to 30mL and are available in quantities of 25, 50, 100, 500 or 1,000. They work exclusively with the following Omni laboratory homogenizers:

• Omni TH (Tissue Homogenizer) – a handheld 125 watt motor with variable speed control from 5,000 – 35,000 rpm. This laboratory homogenizer is available with 12 Omni Tips in the Omni Tip Homogenizing Kits.

• Omni THQ (Digital Tissue Homogenizer) – an ultra-quiet handheld tissue homogenizer with a digital speed readout and extremely accurate repeatability. This homogenizer is sold with 12 Omni Tips and a convenient storage case.

• Omni Prep Multi-Sample Homogenizer – this programmable unit homogenizes six-samples at a time. It is ideal for laboratories with high sample throughput.

What could be worse than relying on a piece of laboratory equipment and when you need it most, it doesn’t work?-Knowing that this disaster could have been easily prevented.

Everybody knows the best way to get maximum efficiency and use out of your car is to keep it properly maintained. Yet when it comes to lab homogenizers, maintenance is often overlooked. I know there is a big difference between your Honda and your homogenizer, but both are complex machines that contain several moving parts. Moving parts will eventually wear out. (more…)

The LH96 is a fully automated laboratory workstation that can be configured to batch process up to 192 samples (dependant upon sample tube sizes).  This new product homogenizes samples using four brushless motors, which will be able to independently power disposable and stainless steel Omni Tip™ style generator probes.  Brushless motors will greatly reduce the amount of noise inside labs, and will allow consistent processing of samples using patented Omni Tip™ products.  When comparing this sound level to four conventional motor drives, you will experience a significantly quieter lab environment.

Operator error can result from manually homogenizing a large number of samples per day.  Having a fully automated homogenizer in your laboratory will allow you to load the unit and walk away while it processes your samples.  This in turn will allow you to do something else productive.

Since the LH96 has a small footprint, it is small enough to fit under most fume hoods and can process sample tube sizes ranging from 0.25mL to 50mL.  When processing 192 samples in 15mL tubes, cross contamination is always a concern.  Therefore the LH96 has a built-in drip prevention and capture pan.  Having this feature drastically reduces the possibility of cross contamination when processing 192 samples (0.25mL < 15mL) or 96 samples (15mL < 50mL).

The LH96 is powered by a micro-processor which has a universal power input, accepting 115 and 220 volt power.  Its touch screen interface is controllable; allowing the user to vary tip speed from 500 to 30,000 rpm, processing time, probe depth, vacillation, dimensions, etc.  Upon determining a custom program that works well with a specific sample, the user can store that program within the memory of the LH96.  In addition to these controls, the interface will inform the user to the machines elapsed run time, time to completion, probe speed, etc.

Having this type of technology on-board allows configuring additional accessories to the unit (which I will explain in my next blog).  To give you a sneak peak however, some of these add-on accessories include the following:

·         Fully Automated Liquid Handling

·         Bar Code Scanning

·         Sample Weighing

·         Cooling Rack

·         Cleaning Station (for Stainless Steel and Disposable Probes)

If you are homogenizing in a high throughput environment, then the Omni LH96 is a perfect fit for your lab.

In my last blog I wrote that I would be back with some Ultrasonic Homogenizer Applications and here I am, back again, trying to fill the Ultrasonic void.

Although Ultrasonic Homogenization is most widely known for disruption of cells and tissue, there are many other uses for it that covers a wide range of applications.

Emulsifications

Water in oil emulsions are well suited for sonication because there is little danger of the sample being ruined by inversion and the process is considerably faster than traditional mixing methods.  The cosmetic industry uses Ultrasonic Homogenization for liquid make-up in order to disperse the pigments uniformly.  It is also widely used by lotion and toothpaste manufacturers as the final product has a much longer shelf life and is a higher quality product.

Environmental

Sonication is used in environmental testing labs for testing of water, soil and sediment samples.  Testing that was done prior to Ultrasonic Homogenization was very time consuming and required high volumes of solvents. The use of Ultrasonics cut the testing time by many hours down to 5-10 minutes making the environmental labs more efficient and reduced solvent waste products.

Pharmaceutical

Pharmaceutical research covers a wide range of applications for Ultrasonics.  Common uses are mixing of powders and solutions, the making of smaller crystals for drug compounds, and degassing samples.  The production of liposomes or lipid vesicles that are used to study mechanisms for drug discovery are also critical in this industry along with putting complex compounds into solution for analysis via chromatography.

Focused Cleaning

This may be the least well known application for Ultrasonic Homogenizers.  In an Ultrasonic Bath the strength of the sonication waves are limited for this type of application.  It takes much more time to clean items in a bath than it would if using a probe type Ultrasonic.  The benefits of this are apparent when trying to clean items with very small openings such as needle or wire dies and electronic components as the energy can be focused and directed by moving the probe.

Check back in a few weeks for part III of the Ultrasonic Blog, “What Equipment in Right for You” and in the meantime have a Happy, Healthy and Safe Holiday and New Year!

It is no secret to researchers who homogenize tissue samples as part of their regular laboratory routine that the job can be messy and loud, and produce results that are sometimes inconsistent. To improve the laboratory work experience, we took a fresh look at the factors that matter most to those who use our homogenizers. These factors include sample processing results, repeatability, ease of cleaning, product noise, time, ease of use, product weight, reliability and environmental impact.This analysis resulted in the creation of the new Omni THQ lightweight handheld rotor stator homogenizer with Whisper Drive™ technology. Mechanical shear homogenizers, also known as rotor-stator homogenizers are the product of choice for most tissue homogenization applications. They generally consist of a motor and a processing probe called a generator probe. As a knife spins within the stator, it creates a pumping action that pulls liquid into the open end of the generator probe. The probe then forces the liquid out through windows in the stator portion, which sets up a shearing action, much like a pair of scissors. It thereby works to reduce the particle size of sample being forced through the windows.The vast majority of today’s rotor-stator homogenizers are powered by motors that require carbon brushes to make them operate. This technology has been around for many years, and while it is quite suitable for occasional use, it has a number of drawbacks when compared to Whisper Drive™ technology brushless motor that drives the Omni THQ.

When compared to our Omni TH brush motor driven homogenizer, the Omni THQ uses 80% less electricity to drive a 7-mm generator probe. Since its motor is significantly smaller and lighter, the THQ weighs 34% less than the Omni TH, and by eliminating motor brush noise, the THQ is 80% quieter than the TH when both are running at 35,000 rpm. This sound level is roughly equivalent to the sound of a moderate rainfall. Since no brushes are used, no carbon dust is created and the motor is maintenance-free, making it more convenient for the user and providing a longer product warranty.

Improved accuracy and repeatability are other significant benefits of Omni’s Whisper Drive™ technology since the motor accurately maintains its set speed, while a brush motor’s speed will fluctuate as sample viscosity changes, or as sample particle size varies. With the THQ a digital display takes full advantage of this accuracy improvement.

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The term “homogenize” is a general term, broadly used to represent processing samples uniformly, usually by means of mixing, emulsifying, stirring, disrupting tissues, lysing cells, or various other methods.  The majority of researchers we speak with have not had previous experience with a specific laboratory homogenizer product in the past, and thus may not know which product or method is most suitable for their application.

Where does one start?  In today’s market choices abound. Here are several important data points to consider before deciding what to purchase, and who to purchase from.

• Application info – does the company or organization you’re speaking with have previous successful experience processing samples similar to yours? Do they have application data they can reference?
• Testimonials – Can they reference customers using their products?
• One Stop Shop – does the company offer several different types of homogenizing methods, as well as accessories?
• Customer-centric – does the company have experienced technical people available to answer your questions, both pre and post sale? Will they offer a solution to meet your needs? Can you try the product before you buy? Do they offer a guarantee?
• Reliability – how long have they been in business? Do they offer service for the product? Where is the product manufactured?
• Availability – once you choose, are these products readily available (off the shelf) and if not, how long will you have to wait? Can you buy through your own preferred scientific distributor or do you have to purchase direct from the source? Is online purchasing available?

Pricing is important as well, but it should not necessarily be the main issue. Remember, the key is to find a successful solution to your specific application. Any potential supplier should be able to answer all of the above points to your satisfaction.

In case you haven’t yet heard, Omni International will be introducing the new THQ handheld laboratory homogenizer to the market within the next few months. This new product will have a brushless motor, digital speed control/readout, and will be OmniTip compatible. These features will reduce the amount of noise inside labs, and will allow a consistent processing of samples using plastic and stainless steel OmniTips.

This Rotor/Stator design homogenizes samples using a brushless motor. This allows the THQ to produce a sound level of 60dB at top speed, which is 15% quieter than most motor drives (but not as silent as your ninja lab partner). It also has a universal power input, accepting 115 and 220 volt power, and an optional external battery pack. This battery pack offers a 15 minute battery life at peak power, which allows it to be used out in the field for quick and efficient on-the-spot testing.

Having a digital speed control with a 3 digit speed readout (displaying the set speed, not the actual speed), will allow you to process samples at the same speed repeatedly. When using the digital touchpad, the THQ has a controllable speed (using separate increase/decrease speed controls) anywhere between 8,000 and 35,000 rpm. After processing the sample, the homogenizer can be turned off, but when turned back on, remembers the last speed at which it was running (This means that you can remember what you were supposed to pick up after work today, and it will remember what speed to run the next sample).

The Omni Tip (a mechanical shearing blade assembly) couples directly to the THQ and has the capability of processing samples ranging from 2ml to 50ml tube sizes. In addition, when using the bayonet generator coupling, a user can successfully process a sample using the 10mm generator. Depending on the size of the blade assembly, plastic and stainless steel Omni Tips are available.

Overall, the THQ, which will be introduced to the market in the next few months, will be one of the quietest and most consistent digital speed controlled laboratory homogenizers on the market today.

Stay tuned for our next Blog about the new Omni TH – Handheld Homogenizer!

Many customers who are just starting to investigate laboratory homogenization techniques call us and ask what the difference is between Ultrasonic Homogenization and Mechanical Shear or Rotor/Stator Homogenization.  As we offer both products, it is fairly simple for us to meet the requirements of all the customers whether they need sonication or mechanical shear technology.  Although you may be able to get similar results from both ultrasonic and mechanical homogenizers, the way they create the energy to process the sample is different and can have distinctive effects on the sample and the end result.

Ultrasonic homogenization is created by power that is supplied by electrical energy that is transferred to a probe, usually titanium, where it is converted to mechanical energy.  This mechanical energy shows up as longitudinal vibrations at the tip of the probe.  Once the energy reaches the tip it causes microscopic vapor bubbles that implode and cause shock waves throughout the sample that cause the processing effect or what is called cavitation.

Ultrasonic probes are solid so they have no tearing or cutting capabilities however they are extremely effective on very small samples as the sample has no chance of hiding in a blade assembly.  Sonicators are more effective at processing bacteria and spores along with soil and sediment samples as they have more of an impact effect for breaking the hard walls of these samples. Ultrasonic Homogenizers are also very effective for DNA shearing.  However, they do generate more heat than Mechanical Shear Homogenizers so heat sensitive samples must sometimes be cooled.

Rotor/Stator Homogenization is driven by an electrical motor that is used to drive a long shaft with a rotor/stator (blade assembly) attached to the bottom of it.  This motor causes rotation of the blade assembly at very high speeds anywhere from 5,000 rpm’s all the way up to 75,000 rpm’s.  The blade (rotor) which is rotating pulls the sample into the processing area and then forces it through very sharp windows in the outer blade assembly (stator) to fully and continuously process the sample.

Mechanical shear homogenization is usually better suited to samples that need a tearing or cutting effect on them.  Examples of these samples include animal tissue and cells such as mouse organs, tumors, and muscle.  It is also very useful for making emulsions and combining powders and liquids along with other general lab applications.

Did you like this article? Stand by, our newest Ultrasonic article entitled “Getting Specific: Ultrasonic Homogenizer Applications” is coming soon!

Designed to Save Time, Improve Yield, and Eliminate Cross-Contamination

by Karl Jahn

Rotor–stator technology is a highly efficient method utilized by many laboratories to homogenize, disrupt, emulsify, and blend a broad range of samples, including tissue samples. As a result, rotor–stator homogenizers are used whenever possible for most laboratory homogenizing tasks. Sample processing times are generally very short, homogenization is fast and efficient, and sample temperature rise is minimized or eliminated. First invented by Prof. Peter Willems in 1957, rotor–stator homogenizing remained relatively unchanged for nearly 35 years.

Plastic Homogenizing Probes

In 1992, Omni International, Inc. (Marietta, GA) invented the first plastic rotor– stator homogenizing probes, known as the Omni Tips™ (Figure 1). This marked the first significant improvement to this venerable technology and completely revolutionized rotor–stator homogenization (patent numbers 6,398,402 B1 and 6,863,431). Stainless steel homogenizing probes, still used in many laboratories, usually require a tedious cleaning step between samples. This may involve complete probe disassembly, especially if autoclaving is necessary. After cleaning, the probes must be carefully dried and reassembled. Even when meticulously cleaned, sample-to-sample contamination cannot be totally eliminated, and the complex geometry of stainless steel probes leaves many places for contaminants to hide. Plastic Omni Tip probes, on the other hand, can be disposed of after use, thereby eliminating the possibility of cross- contamination. Further, the use of modern engineering plastics enables the probes to be cleaned and reused. When chemically cleaned, Omni Tips can be reused dozens of times, and can be autoclaved up to seven times. The probes require no bearings, and simple two-piece construction allows for easy disassembly and cleaning. This simple construction also reduces the potential for cross-contamination by a factor of four when compared to stainless steel probes.

With a trend toward smaller and more valuable samples, sample loss can be a real source of concern for some laboratories. The design of Omni Tip plastic probes offers the additional benefit of a clear outer tube, thereby keeping the entire sample visible during the homogenization process and ensuring that sample is not lost within the probe. A second trend, particularly in laboratories with scarce financial resources, is equipment sharing. With stainless steel probes researchers are never quite sure what was most recently processed, or how clean the probe is. The low acquisition cost of Omni Tip plastic probes means that laboratory homogenizer motors can now be easily shared, while each researcher can use his or her own Omni Tip probes. Further, stainless steel probes can easily cost more than a thousand dollars, and can be damaged if not effectively maintained and cleaned. A mere six-inch drop can permanently damage a stainless steel probe. The Omni Tips can readily survive a drop in excess of six feet and remain fully functional. Many laboratories also value consistent sample-to-sample processing. Stainless steel probes wear with use, particularly in the lower bearing area. The PTFE lower bearing is responsible for centering the probe knife during processing.

As the soft PTFE material wears, the spacing between the rotating knife and the stator begins to change, leading to variable processing results. Omni Tips are molded to rigid standards with virtually no dimensional probe-to-probe variability. As a result, they tend to yield highly repeatable processing results.

The plastic probes are available in a soft tissue version for sensitive cell disruption and in a hard tissue version, tough enough to process frozen tissue as well as most other applications that previously required stainless steel probes. Omni Tips spin at 35,000 rpm, which is the same speed as their stainless steel counterparts. For aerosol containment, a broad range of sealed tube solutions is available to work with the probes.

Omni Tips are very economical to own and use. Their acquisition cost is about 1% of stainless steel probes, which can be significantly reduced when cleaned and reused. This low cost makes batch processing a highly efficient method for homogenization. Samples can be quickly homogenized, and the probes subsequently disposed of, or batch cleaned for reuse. Elimination of the cleaning step between samples also creates an ideal platform for automation, as with the Omni Prep™ homogenizing workstation (Omni International), which is capable of processing six samples simultaneously, with a capacity of up to 250 samples per hour.

Multi-sample Homogenizer

The Omni Prep programmable homogenizing system (Figure 3) is designed to eliminate homogenizing processing bottlenecks, while also addressing the shortcomings of existing approaches to rotor–stator homogenizing methods. The system is small enough to easily fit into a fumehood, and also preserves precious laboratory bench space. It is designed around a rack system that allows six samples to be processed simultaneously. By utilizing a second processing rack, six more samples can be prepared while the first rack is processing, permitting a single operator to process up to 250 samples per hour. Operator fatigue and repetitive motion injuries that can result from homogenizing a large number of samples per day by hand are also eliminated, while a single technician can now perform the work of six. The racks are designed to accommodate a broad range of tube sizes from 1.5-mL microcentrifuge tubes up to 50-mL conical bottom tubes, and are available in fixed or movable configurations. The fixed rack is well suited for processing samples that require sealed tubes, while the movable version is intended for processing larger sample volumes that require probe mobility within the sample. The recommended processing volume for the Omni Prep is .25 mL up to 30 mL. A cooling tray is also offered to keep sensitive or frozen samples cold during the homogenization step. A clear plastic door protects the operator from accidental splashing, and a fan-driven positive airflow pattern move air away from the front of the instrument for exhaustion into a fumehood or through a HEPA filter.

Reference

1. Mace, B.E.; Sullivan, P.M. The Use of Steel Homogenizer Probe Results in Sample Carryover Contamination. Duke University
Medical Center, Durham, NC, 1997.