Lab Tools

While we’ve built our business and our reputation on the strength of our lab glassware, we at DWK Life Sciences know the important role that lab tools and accessories play in your success. That’s why we’ve assembled a wide selection of precision tools to help ensure the accuracy and repeatability of your results. From staining dishes to crimpers, dispensers to stopcocks, we’ve got you covered. We put just as much thought and innovation into these lab basics as we do into our industry-leading glass components. That’s why our bottle-top dispensers combine the latest in dosing technology and comply fully with current safety regulations. It’s why our tissue grinders are available in both reusable and disposable plastic, sterile and non-sterile versions. And it’s why many of our lab tools have replacement parts available — an innovation in lab economics.

Lab Tools that Get the Job Done

If you’re looking for a tissue grinder, there are several to consider: Dounce, Potter-Elvehjem, tapered, Tenbroeck, and pellet pestle. Here at DWK Life Sciences, in addition to the reusable glass tissue grinders, we also offer disposable plastic grinders in sterile and non-sterile versions from 0.1 mL to 55 mL, and the Dounce Dura-Grind™ tissue grinder in precision-machined stainless steel. Be advised, this lab tool cannot be autoclaved/sterilized.

For soft tissue such as the brain or liver, we recommend the tapered tissue grinder with a steel rod and borosilicate glass mortar. The rod can be used with powerhomogenization and, for your convenience, the components are interchangeable. This unit can be autoclaved/sterilized to prevent cross-contamination between samples.

Pellet pestles are single-use plastic homogenizers used to resuspend protein and DNA pellets or grind soft tissues in microcentrifuge tubes. These practical options are available in both sterile and non-sterile.

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Because crimpers and decappers are part of every lab’s essential tool collection, we’re happy to offer a full selection, from manual to high-performance options. Our manual hand crimper and decrimper for aluminum seals and vials is available for 11, 13, and 20 mm size caps. These are perfect for chromatography and general crimping needs. If your work requires something a bit more robust, then our battery-powered crimping tool is recommended with up to 800 crimps per charge and convenient LCD controls on top of the unit to make adjusting the crimp easy. The fastest and most powerful lab crimping tool we offer is our high-performance model — strong enough for all steel and magnetic caps. We’ve designed it with an external power source and a selection menu that displays the different types of jaw choices on an a LCD screen. For flip cap seals, the manual crimper / decapper will accommodate up to 30mm.

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WHEATON® bottle-top dispensers are a versatile lab tool designed for performance handling of liquid from a large variety of bottles and flasks. Our dispensers employ the latest in dosing technology, and are manufactured and tested to fully comply with current safety regulations. The click-stop mechanism prevents unwanted alteration when dispensing. For your convenience, all models provide a selection of three color-coded sizes and extensive

DWK Life Sciences offers a full line of manual and electronic pipetting that is more versatile, simpler, and safer than ever. Acura® micropipettes have a reduced shaft length and conical end with improved drivability. The macropipette has an interchangeable nozzle protection filer and can be adapted for Pasteur pipettes and straw tips. The lightweight multichannel pipette has a large selection of 8- and 12-channel models.

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DWK Life Sciences microscope slides are made from high-quality soda-lime glass and are designed for single use only. Choose from cut edges or ground edges at either 45° or 90°. Our coverslips are made of borosilicate glass and are used to fix preparations during microscopic examinations. These premium covers ensure the distribution of droplets on the microscope slide. The selection of staining dishes includes our Coplin staining jar 5-10 slide unit to a slotted rack that holds 50 slides. Add in our Columbia jar for coverslips and our slide grip that fits Coplin staining Jars (900570, 900470, 276840), and you’ll see that we have the lab tools you need. For your convenience, marking areas are available as a frosted end or colored (yellow, white, blue) and adhesive with a standard coating is available.

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Whether you’re looking for one-way or four-way stopcocks, PTFE or glass plugs, metering plugs, or Hi-Vac® valves, you can depend on DWK Life Sciences to provide the highest quality glass stopcocks and valves. The DURAN® stopcock, with PTFE spindle for desiccator base, side outlets, and lids, is available to fit a 24/29 neck. Our threaded Bevel-Seal™ connector with PTFE stopcock has an overall length of approximately 80 mm and is manufactured from 3.3-expansion borosilicate glass. Money-saving replacement plugs are available in size 2 and 4. The T-Bore 90° stopcock with a solid glass plug is precision ground for pressure applications.

DURAN® one-way valves are designed for use as on-and-off valves. The PRODURAN® 90° valves have a height-adjustable spindle with a fine thread, which allows the finest adjustment of the valve opening. The PRODURAN® valve tap is suitable for a high vacuum in combination with the thick-walled attachments. The composite system made of borosilicate glass 3.3, metal, and plastics means that the media flowing through the valve only come into contact with borosilicate glass 3.3 and PTFE, allowing for a grease-free operation. The innovative construction of the valve makes it handy, easy to release, and dismantle. In fact, the unscrewing protection prevents absolute unscrewing of the valve pin and the adjustable valve pin increases the service life of the valve tap.

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Frequently Asked Questions

Although it is possible to convert your crimper by replacing the internal crimping jaws and plunger, it is not advisable. Manufacturing uses special fixtures to help assemble the components.

There is a special crimping head for aluminum seals with the plastic closures that is often termed a flip-off crimping head. Please make certain your crimping head has the jaws with the internal recess for the plastic button that is part of the seal.

The easiest way would be to measure the diameter of the plunger. The plunger is approximately the same diameter as the seal and contacts the top of the aluminum seal during a crimping operation.

Usually, the indentations are is caused by over-tightening. We suggest that you try adjusting the crimping tool for a looser seal.

Crimp closures are generally well known for their excellent sealing characteristics — an absolute must maintain parenteral content integrity and long-term sample storage. It has to be noted, however, that the quality of a crimp seal is strongly dependent on the right calibration of the crimping tool used to apply the closure to the vial. To maintain good results, make sure to re-calibrate your crimping tool regularly and check the quality of the seal every time you crimp. The best way to know if your vial has been crimped properly is to visually inspect the overall appearance of the crimp.

An optimal crimp result is characterized by the following features:

  • The cap surface is flat.
  • The sides of the cap fit tightly around the vial neck and do not show any deformations.
  • The septa is not being sucked into the vial nor does it emerge out of the center hole.

Many of our customers rely on the so-called “turning test” or “twist test” to verify the crimp result. To test the quality of the crimp, the vial is held in one hand while the other hand is used to test whether the crimped cap can be turned or not. A cap which does not turn indicates a good crimp.

Warning: this test is not very meaningful for two reasons:

  1. Many septa come with a PTFE lamination. Due to the smooth surface of the PTFE membrane, the cap can be turned even if the cap was crimped correctly.
  2. An over crimped closure which passes the turning test will have impaired sealing characteristics due to the deformation of the cap and septa.