“Time is the fire we burn in.” Despite the fact that we may be unable to quench its unrelenting flame, scientists have tried to divert its path by isolating small enclosures where time slows to a crawl. Within these chambers the frenetic Brownian dance is a chaperoned waltz, as temperatures approach absolute zero. The interior environment of Air separation equipment can be a world apart, a reminder of your ultimate heat-death that has to befall our universe inside the eons ahead.
For those who attempt to discover truths about the workings from the cell, holding back the floodgates of time is a concern of significant proportions. Scientists are often enthusiastic about very specific cell properties that transpire at critical junctions inside the lifetime of a cell. Holding these processes under control while their properties could be exploited is similar to the issue of catching one’s shadow.
Cryogenic freezing of cells has been used as one answer to the issue in the slow burn. By reduction of temperatures of samples to the glass transition phase of -133°C, the temperature in which all metabolic activity goes to a halt, scientists can easily seclude moments soon enough, returning time and again to research that instant in history.
Not surprisingly, cryogenics has grown to be a significant industry that creates customized products for almost every conceivable purpose. From small tabletop apparatus to industrial-scale liquifiers, the current market in cryogenics provides mechanical freezers, canisters, and dewars in every single size, shape, and configuration imaginable. With such a multitude of products to pick from knowledge of which ones are best may elude the normal consumer. So that you can provide an overview of the most important producers of cryogenic laboratory supplies several manufacturers will probably be profiled in the following paragraphs.
Ultra-low lab freezers are one of those particular stuff that a lot of people never take into consideration until they quit working. Designed to run for many years without interruption in service, lab freezers would be the quiet sentinels in the laboratory, keeping a vigilant watch on the researcher’s most prized possessions. Most scientists attempt to avoid the very thought of what might happen if their freezer failed, or they attempt to erase the memory during the day in the event it did. A career’s worth of samples could be lost within a afternoon– several years of careful collecting and cataloging reduced to mere puddles on to the ground. Even though this type of scenario looms ominously within the periphery of each and every researcher’s consciousness, not many are prepared for a day when it actually occurs. Manufacturers of ultra-low lab freezers have taken great pains to ensure that power failures and refrigerant leaks will never compromise one’s samples. They build machines that usually are meant to be forgotten.
MMR Technologies may be the only company which uses the Kleemenko cooling cycle in their refrigerators. Even though the natural gas industry has used this method for several years, MMR Technologies was the initial company to patent the technology and adapt it for very small, lightweight, and portable freezing systems.
The way the Kleemenko cycle works is the fact an assortment of compressed gas and liquid is passed down a countercurrent exchanger and is capable to expand through a capillary or throttling valve. Cooling occurs upon expansion, as well as the cool gas passes backup the high temperature exchanger, precooling the incoming high-pressure gas. A number of liquid-vapor separators might be incorporated in the cycle in order that the increase of the liquid may be used to precool the vapor (W.A. Little., Presented at ICEC17, Bournemouth, U.K.,July 14-17 1998)
The BIO 120 is a zero-maintenance, low-power-consumption Kleemenko refrigerator that is ideal for storing frozen tissue, cell cultures, organs, and the body parts. The unit allows the scientist to warm and funky samples uniformly without shocking them, and since they have an inside power source it can be used to the transportation of samples from storage facility to research laboratory. Robert Paugh, product manager for MMR Technologies, was insistent on the demand for controlled temperature ramping.
“As being a user you wish to are aware of the minimum temperature and the way it gets there,” said Paugh. MMR Technologies’ enhanced control systems and printed thermal record of cooling makes sure that uniform temperatures happen to be maintained during the entire cooling process.
Kelvinator Scientific, which is actually a subsidiary of Frigidaire, provides freezer units for laboratories and pharmacies that are equipped for biological samples at temperatures right down to -86°C. At temperatures this low animal and plant viruses, bacteria, spores, and bacteriophages may be preserved for long periods. Locking lids are offered in order to protect samples from accidental being exposed to ambient temperatures. Adjustable shelving, pullout drawers, and drawer partition inserts are useful for separating different experiments.
NuAire, Inc. credits a great deal of its ultralow freezing capabilities to its heavy-gauge galvanized steel cabinets. The temperature-conducting quality of the material reduces stress on compressors allowing the units to perform longer and colder than would otherwise be possible. Maintaining temperatures at -152°C the NuAire ultralow freezer is capable of doing holding samples underneath the crystallization point.
In line with the Clean Air Act of 1990 for systems using HCFC/HFC refrigerants, NuAire also relies on a special mix of azeotropic gases that happen to be non-flammable and permit on-site recycling. In addition, a built in timer cycles the low stage compressor every one day, turning it away so the capillary tubing will be cleared of ice formation.
So-Low Environmental Equipment Co. features a long tradition of creating ultralow freezers for laboratory applications. Actually, with 40 years of expertise under its belt, So-Low is one of the oldest manufacturers of ultralow temperature freezers in the commercial. If the Montreal Protocol started the phase out of CFC refrigerants in 1987, So-Low was one of the primary to work with Dupont Suva 95, the latest CFC-free refrigerant that runs cooler together with less pressure than CFCs. In addition to its investigation of eco-friendly refrigerants, So-Low has additionally developed a modern compressor that is certainly designed just for its ultralow freezers.
Forma Scientific offers both mechanical and liquid nitrogen storage systems for preserving samples at ultralow temperatures. The mechanical freezers preserve specimens to -86°C, while Forma’s liquid nitrogen freezers store samples at -133°C. Unlike its competitors’ liquid nitrogen freezers, however, Forma provides square cross-section units rather than the typical cylindrical containers. All these cabinets is constructed of cold-rolled steel. Forma’s counterbalanced lids provide quick access, an optional thermal data printer continuously documents all operational functions, along with a storage system adjusts to support a selection of tube sizes. Forma also provides a patented double door unit that separates lasting from everyday storage.
Revco is one of the largest manufacturers of laboratory freezers with more than 50 years of expertise in the business. Revco’s Elite, Value, and Ultima mechanical freezers sustain temperatures from -10°C to as low as -120°C without CFC refrigerants and can be found in chest, upright, and tabletop models. Its sophisticated Ultima freezers offer automatic electronic systems that constantly adjust conditions for the internal and external environment, correcting for subtle fluctuations in ambient temperature, excessive loading with warm samples, and dirty filters. Furthermore, it includes a scrubbing cycle that removes vaporized lubricating oil in the evaporating coils.
Sanyo has become manufacturing laboratory and medical freezers more than 2 decades, starting with its manufacturing of the very first -40°C chest freezer in 1974. Sanyo duplicated this achievement with the creation of the initial -152°C ultralow temperature freezer in 1991 and additional demonstrated its position by becoming the very first manufacturer to offer a complete range of CFC-free medical freezers. Today, Sanyo offers one of the largest selections of ultralow temperature lab freezers now available. Sanyo’s upright and chest freezers are designed for use within preserving cells, bacteria, spores, pollen, sperm, protozoa, and blood components for academic and industrial research.
The word dewar, originally placed on double walled glass vacuum flasks, is now put on a variety of insulated vessels created for maintenance of samples in liquid nitrogen. Depending upon their size, dewars usually rest on to the floor or take a seat on tabletops where samples can be simply accessed. As a result of quality of insulation materials, some dewars have maintained critical temperatures so long as 1 year without having to be regenerated with liquid nitrogen. The typical thermal wall is made up of an aluminum or steel sandwich full of polyurethane. The size and configuration of dewars vary to this sort of extent that numerous companies build custom dewars to buy. Many of these companies as well as their merchandise is reviewed from the following section.
From Alaskan salmon eggs to embryos from Idaho’s chicken farms, MVE makes laboratory freezers for numerous types of applications. Obviously, animal breeders are simply a small portion of its customers. Blood and cell storage along with organ shipment are an equally large part of MVE’s business with medical and pharmaceutical applications representing the quickest-growing area of the industry for the company’s products.
MVE was the 1st company to build up biological freezers effective at maintaining a -190°C environment for any full year without refilling with nitrogen. Since this time MVE has released the entire brand of XLC series liquid and vapor-phase freezers. The XLC liquid nitrogen freezers are capable of handling as much as 36,000 vials at temperatures as little as -195.8°C. The vapor-phase freezers are fitted to cells that may be stored at -125°C but will become damaged or discolored at critical temperatures achieved by liquid nitrogen freezers. The vapor-phase freezers will also be helpful for storing hazardous materials which may cross-communicate in a liquid medium, such as contaminated-blood bags that are liable to break open.
Quantum Technology can be a worldwide manufacturer and supplier of laboratory freezers with offices in america and Germany. Its product line includes everything from compressors and temperature sensors to gas wells and vacuum shrouds.
Based on Sean Wolf, product manager for Quantum Technology, one of the ways his company has were able to remain competitive is as simple as offering on-site service and warranty repair. Another major selling point of Quantum’s refrigeration systems is simply because they could be custom designed.
Certainly one of Quantum Technology’s most widely used products can be a helium recovery system. Although liquid helium is only $4 or $5 per liter, in numerous countries outside of North America and Europe, the expense of purchasing helium is a concern of concern. That is probably the main reasons why Quantum Technology makes an effective two-stage and three-stage closed-cycle refrigerator wherein the helium is retained within the system. The helium with this refrigerator is reliquified for use repeatedly.
Lab-Line Instruments, designer and manufacturer of dewars for scientific research and recently acquired subsidiary of Barnstead Thermolyne, offers a Thermo-Flask line of goods that include wide-mouth flasks, insulated Thermo-Cups, steel Thermo-Flasks, and enameled steel Thermo-Flasks. Twenty-six different types are offered with capacities from 200 cc to 10 liters, and each of these models is accessible having a 24-month warranty. Other special features of the Thermo-Flask line of products include vented lids to avoid pressure build-up, fold-down handles, and borosilicate inner vessels evacuated to offer coolant retention for samples stored in liquid nitrogen or solid CO2.
Barnstead Thermolyne manufactures the Bio-Cane and Locator Plus cryogenic storage systems, which are distributed by a number of companies throughout the us. The Bio-Cane systems are available in five sizes and present features such as super vacuum insulation, ampule cans, a polycarbonate lid, and color-coded canisters for inventory identification. The Locator Plus storage systems are available in four sizes and get capacities up to 6,000 vials. Together with a number of the standard features contained in the Bio-Cane, the Locator provides hanging racks having a gridded box design, audible and visual alarms that warn of low-level conditions, and an ultrasonic liquid level monitor that eliminates connection with liquid nitrogen and consequently reduces evaporation.
Pope Scientific makes a number of traditional dewar flasks in “cylindrical,” “low form shallow,” and “spherical” styles. All Pope dewars are made of borosilicate glass protected by a protective mesh, and each and every wide-mouth model features a vented polyethylene stopper to reduce evaporation. Wide-mouth dewars can also be jacketed in aluminum casing for additional safety.
Pope Scientific’s narrow-mouth or “constricted-neck” dewars are designed for temporary storage or transfer applications with holding times above fourteen days. Many of these units come equipped with the lowest-evaporation stopper, a totally shielded evacuation tip, a weighted base, and protective mesh. Options for these instruments include fiberglass caddies for carrying or decanting.
Taylor-Wharton International makes the K Series, XT (Extended Time), HC (High Capacity), and RS (Rack System) dewars that enable the researcher to save large quantities of semen, embryos, and biological samples at liquid-nitrogen temperatures. Every one of these units is complemented by its unique inventory control system, which is made to maximize the quantity of vials that could be safely arranged into a canister-type storage device. By either immersing samples in liquid nitrogen or suspending them in nitrogen vapor, vials can be maintained at temperatures of -196° C.
Cryogenic Tubes are among the most often used and least considered implements in the researcher’s tool box. Bags of tubes are stuffed into corners and forgotten until they mysteriously run out a day. Then it is time to look shopping. Making decisions about buying cryogenic tubes is generally guided by three primary issues, the very first which concerns the challenge of if they are externally or internally threaded. Advocates of externally threaded vials advise that material is trapped inside the threads of internally threaded vials, while proponents in the internally threaded sort debate that externally threaded vials will be more easily contaminated by accidental contact. Although reports have been conducted in an effort to confirm or refute these claims, these have not been conclusive, along with the debate proceeds.
Another consideration which comes under consideration when buying cryogenic tubes will be the material that these are constructed. While plastic vials are, perhaps, more durable than glass, they take more time to warm which can negatively impact the viability of some cells. Some plastic tubes may also be contaminated with releasing fluids during the molding process. However, releasing fluids are easy to remove with the care, and a few businesses like Axygen are switching to new polished molds which do not require the use of releasing fluids. Glass, on the other hand, warms rapidly but is additionally subjected to fracture as a result of microchannels which could form within the glass, causing leakage of sample contents, as well as violent explosions. Plastic vials can also be susceptible to nitrogen penetration but the potential for explosion is not really as great.
Gasketing has also been a challenge of some contention in this industry. Many cryovials come with a washer that keeps the inner pressure of your vial from expelling the tube’s contents after it is warmed to ambient conditions. The rapid expansion of gas in the tube is sufficient to force cells and fluid through the lids of several non-gasketed cryotubes. Silicon is generally preferred as the best material for insulating caps against leakage. Although rubber is additionally used, it possesses a tendency to shed its elasticity when dropped to freezing temperatures, a challenge which had been demonstrated as soon as the “O” rings about the space shuttle Challenger failed.
Simport Plastics, headquartered in Quebec, offers a large choice of cryotubes and microcentrifuge tubes which you can use at temperatures as low as -190°C. Made for handling biological samples under freezing conditions for prolonged periods, its Cryovials™ come equipped with attached leak proof caps that contain a dual lip plus a silicon washer. A special ridge on each cap makes handling easier, leading to one-hand aseptic technique, and color-coded cap inserts in combination with white marking areas make each vial easily identifiable.
Evergreen Scientific manufactures the CryoSure® brand of vials for storing cell cultures, blood/serum specimens, sperm, as well as other biological fluids at vapor-phase liquid nitrogen temperatures (-195°C). CryoSure vials can be purchased in 1. ml, 1.5 ml, and three.5 ml sizes and are available in round-bottom and freestanding configurations.
Evergreen even offers a wide array of microcentrifuge tubes that range in capacities from 250 µ l to 2. ml. Some examples are polypropylene tubes, which can be used in combination with solvents, alcohols, chlorinated and aromatic hydrocarbons, and ketones. These tubes are sterilized using gamma radiation and therefore are pressure tested inside a vacuum chamber to ensure the reliability of its double-sealing screw caps.
Evergreen has recently designed a new microcentrifuge tube, in cooperation with Washington University Lipid Research Center, for usage in lipid fractionation studies. It really is a 1.5 ml polystyrene tube with the 11 mm high-density polyethylene cap. One of several outstanding features of this tube is it is entirely transparent.
Nalgene® and Nunc™ cryogenic vials include a variety of externally and internally threaded vials from 1. to 5. ml capacities which can be silicone gasketed and guaranteed to use in the centrifuge. The Nalgene 5000 series vials feature graduations and they are certified being sterile, noncytotoxic and nonpyrogenic, while the System 100 vials are sure to be leakproof in the microcentrifuge approximately 8,000 g and throughout shipment and transport. However, the business warns that cryotubes improperly sealed in liquid phase could lead to an explosion or biohazard release. Nalgene and Nunc have provided CryoFlex Tubing to avert this contingency.
Wheaton Science Products makes tubes and flasks for almost every eventuality. From serum bottles to mobile phase reservoirs, it provides developed a comprehensive catalog of merchandise for handling liquid samples. Wheaton’s Cryules® are available in both plastic and glass. The glass Cryule is manufactured out of Wheaton-33° low extractable glass that can be hermetically sealed. They are suitable for that preservation of biological materials with liquid nitrogen at low temperatures. Wheaton’s plastic Cryules are autoclavable and, like all of the glass Cryules, can withstand temperatures between -196°C and 121°C. Wheaton Vacules are vials which are constructed for lyophilization and freeze-drying. Their heavy-wall construction makes them exceptionally durable, and they can be flame sealed or stored having a wide selection of stoppers and caps.
Corning Incorporated Science Products Division makes several polypropylene vials that are equipped for use at temperatures to -196°C. These come provided with a number of features including color-coded caps, silicon and rubber washers for secure sealing of contents, as well as simple-to-read graduations for partial volumes. Self-standing and locking features can be purchased with selected styles. All of Corning’s vials are supplied sterile and certified as nonpyrogenic.
Axygen Scientific Inc. makes microcentrifuge and screw-cap tubes for storing samples at subfreezing temperatures that happen to be designed with 99.9 percent pure polypropylene with no mineral fillers or heavy metals. Foreign substances are added limited to the request in the customer, and Axygen’s colorants contain no metallic ions like iron, chromium, or nickel that happen to be typical constituents of dyes. All of the company’s vials is designed to snap closed inside a locked position for centrifugation, and special piercing ports have the insertion of syringes easier for collecting samples. Axygen’s “O” ring closure system includes a patent-pending alignment system that guarantees that the microtube is aligned inside the centrifuge rotor to get re-spun without disturbing the pelletized sediment.
Sarstedt Inc. posseses an extensive catalog of microcentrifuge tubes which are right for both freezing at ultralow temperatures and centrifugation that come in a big selection of sizes, shapes, and colours. The consumer has the option for selecting from a number of externally threaded microtubes with attached or enclosed screw caps that could be colored for identification. Each one of Sarstedt’s tubes are sterile, and the polypropylene material from where they are constructed enables them to endure subfreezing temperatures along with temperatures and pressures within an autoclave. Among the areas that Sarstedt has paid particular focus on in developing its collection of products is the requirement for cryogenic vials which contain reaction buffers and enzymes for PCR applications.
Stockwell Scientific manufacturers CRYO-LOK® Cryogenic Vials and screw- cap microcentrifuge tubes for storage and transport at ultralow temperatures. These range in capacity from .5 ml to 3.5 ml and can be found in conical and skirted configurations. Stockwell’s microcentrifuge tubes might be exposed to a centrifugal force of 20,000 g and every one of its O-ring sealed tubes has been sterilized.
Storage inventory systems certainly are a critical component of any long term protocol for cryogenic preservation. Once cryogenic vials are stored at subfreezing temperatures they might undergo changes which make them hard to keep trace. Labels could become brittle, breaking and separating from vials, and improperly stored tubes can be dropped into liquid nitrogen making retrieval difficult and costly. One of the most popular methods for containing samples may be the canister and cane. Applying this technique, several vials are enclosed in a long aluminum shaft which is submerged within liquid nitrogen. The canes can be simply manipulated for small sample volumes and protect vials from damage which may occur from bumping or agitation. For greater storage capacities, however, the drawer method is usually preferred. Although drawer systems have a tendency to expose more samples to warming during exchange, the accessibility from the system reduces exposure time and energy to ambient temperatures resulting in less evaporation in the freezer, as well as lessens the researcher’s exposure to possibly damaging cryogens.
Forma Scientific makes rack inventory systems for liquid-phase and vapor-phase storage. These racks are created to optimize the level of space for storing afforded by Forma’s liquid nitrogen containers. The conventional inventory configuration is actually a cardboard or steel construction arranged into arrowhead or square designs. Vertical inventory systems allow the user to set up up to 82 racks at maximum density.
TetraLink International focuses on making storage boxes and rack systems for cryogenic storage. Intended for the widest possible applicability, its freezer storage systems can be found in a variety of sizes, shapes, and colours to fit almost any freezer. Clear lids allow contents to become viewed without opening the containers, and they could be adjusted in particular models to accommodate tubes of varying heights. Round holes provide spacing with clearance for snap-seal and safe-lock caps. TetraLink’s Racksys storage system uses sliding drawers which contain storage racks for holding as many as 267 microtubes. These drawers might be installed in every upright freezer or refrigerator.
Nalgene and Nunc storage systems comprise several plastic or chipboard containers for microcentrifuge tubes and glass vials. These are typically keyed to stop misalignment and give temperature resistance from -196°C to 121°C.
Nalgene® CryoBox Racks provide stainless retainer systems works with all Nalgene and Nunc storage boxes. They feature vertical and horizontal storage for boxes that maintain each box separately for quick retrieval.
National Labnet provides freezer racks and storage boxes for the increasing selection of sample containers. As high-throughput experiments require greater reserves of reagents, Cryogenic ISO Tank Container has responded with boxes and racks that happen to be constructed for numerous samples of both well plates and cryovials. They also have introduced boxes with telescoping lids in order to satisfy requirements for single box containers with vials of differing sizes.
Custom Biogenic Systems is one of the largest manufacturers of rack systems for cryogenic packing containers. In reality, most of its products are sold as standard accessories with some of the major producers of laboratory freezers. Its pie-shaped racks are made from stainless steel and can include a selection of cardboard, aluminum, or steel boxes with 1/2 inch or 5/8″ cell dividers. These systems can be purchased as individual units or as complete racks for usage in vapor- phase or liquid-phase storage.
Probably, the cryogenic products one buys today would be the same ones that might be used for many years. A purchase made today may continue for decade. In effect, researchers buying Cryogenic Centrifugal Pump are not only buying products for their own reasons, they can be buying for successors. The customer should think about what might 46dexkpky during the period of years if their samples become degraded or contaminated as a result of improper storage. A little money which had been saved at first by scrimping on vials or freezers may well not seem like the best trade off when valuable samples are lost. In spite of the safeguards built-in to the majority of these devices many product managers recommend making regular maintenance on these products a priority. Appointing a permanent position that is responsible for the cryogenic safety of the laboratory’s biological collection is one of the ideal way to assure the integrity of those samples.