FAQ’s
- Does any rack fit any freezer?
- How to maximize the use of my freezer's space?
- What is the advantage of using a locking rod?
- What is a "Large" box and what cell divider(s) will it hold?
- What are the advantages of a platic box versus a cardboard box, including weight difference?
- What are the standard vial sizes and what box/divider will they fit into?
- What is the difference between standard and waterproof cryogloves?
- What is a standard box and what divider will it hold?
- Why are my cardboard boxes damaged?
Does Any Rack Fit Any Freezer?
There are two types of mechanical freezers, upright and chest freezers. Upright freezers have side-loading doors and chest freezers have top loading doors. Also, there are liquid nitrogen freezers that have top loading lids. All of these freezers are designed for racks that store 5 ¼” x 5 ¼” x 2” standard boxes. For example, the interior dimensions of a 21 cubic foot upright freezer is 50.5” high x 24.25” front-back x 28.5” wide and there are five 9 5/8” high shelves. Five Custom Biogenic Systems URO442 racks will fit on each shelf for a total capacity of twenty-five URO442 racks. The dimensions of the URO442 rack are 9 ¼” high x 22 1/8” front-back x 5 ½” wide, and it holds sixteen boxes. If a standard box with an 81-cell divider is used, each box will hold 81 vials. The total vial capacity in the 21 cubic foot freezer is 32,400 vials (18 vials x 16 boxes x 25 racks).
If a scientist selected a 100-cell hinged top plastic storage box for storing vials in the 21 cubic foot freezer, the total vial capacity would only be 24,000. This is because the rack that would fit into the 21 cubic foot freezer is a UHT34 rack. Only four UHT34 racks fit on each shelf – twenty racks total. Also, the UHT34 holds twelve100-cell hinged top plastic boxes. Thus, the total vial capacity in the 21 cubic foot freezer is 24,000 vials (100 vials x 12 boxes x 20 racks).
Standard boxes (5 ¼” x 5 ¼” x 2”) have been used since the 1960’s, the start of -86º C mechanical freezers and liquid nitrogen freezers. Racks and boxes were created at about the same time for storage in these freezers. Glass vials were originally used and plastic vials came soon afterward. The freezers of the 1960’s were designed to store as many vials as possible. Storage racks were created to store boxes and to fit into the freezer shelves. Freezer manufacturers designed their equipment to provide the most efficient capacity of standard box storage.
Does any rack fit any freezer? Possibly, but it may not be efficient storage. Measure your rack dimensions and your freezer dimensions to get the best use of rack storage.
How To Maximize The Use Of My Freezer's Space?
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Learning to organize the space within your ultra-low temerature freezers can help you avoid handling and retrieval problems with your biological samples. Organizing your freezer space can make your work procedures more efficient and even reduce the over-all investment cost in your laboratory equipment. Our experience in dealing with users of low temperature freezers, liguid nitrogen freezers, and dewars has shown the following benefits when they are optimally organized –
Selecting the correct freezer racks and the right type of containers for the racks will optimize the space used in your freezer and provide the other benefits mentioned above. Here, then, are some guidelines and helpful hints for choosing these storage elements for your freezer. |
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How to Select the Correct Rack for your |
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Whether your storage unit is an upright freezer, a chest freezer, or a liquid nitrogen freezer, storing any bio sample without using a freezer rack will not only reduce the capacity for specimen storage, but it will also increase the risk of damaging samples through mishandling. This is true whether you are storing bone marrow, stem cell, cord blood, or any other type of cell or tissue samples. Selecting the correct rack and container will reduce this risk and provide for the maximum use of your freezer space. Here is the process for determining and selecting the best rack for any type of sample storage. |
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1.Determine the type of freezer you have: |
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2. Determine the type of sample container or item being stored: |
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3. Determine whether a box is needed to hold your sample container or item. |
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4. Determine the style of the freezer rack: |
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5. Determine the depth, width, and height of the shelf that your freezer rack will be stored on. When measuring, be sure your freezer is free of ice buildup. This will insure the most accurate measurement of the storage space within your freezer, whether you are storing, vials, plates, microscope slides, or any other type of sample container. |
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6. Finally, determine any desired options for your freezer racks. For instance, one of the options on freezer racks is a locking rod. Locking rods provide a safety feature which holds your boxes or other storage containers securely in place and helps prevent accidental slipping and damage of your stored specimens. |
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Example
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Selecting a Freezer Rack and Determining Maximum Capacity
for Your Available Space (using a 2ml vial storage example) |
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1. Select your type of freezer:
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2. What are you storing?:
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3. Select your box style:
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4. Select your box cell divider:
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5. Determine dimensions of your shelf space: |
Shelf |
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6. Determine model of rack based on box style (#3 above) and the shelf dimensions (#5 above):
The height and depth of the rack must be a minimum |
URO442 Depth: 22.125 Width: 5.50 Height: 9.25 Box capacity = 16 (4 deep & 4 high) |
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7. Determine number of racks that can be stored in your shelf space:
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Freezer width 40 / 5.50 = 7 racks |
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| 8. Determine number of boxes that can be stored in your shelf space: |
Maximum number of racks 7 x 16 = 112 boxes |
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| 9. Determine number of vials that can be stored in your shelf space: |
Maximum number of boxes 112 x 81 = 9,072 |
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Helpful Hints
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| Do not overload your ultra-low temperature freezer shelves with excessive weight. Overloading can cause your shelves to bow, resulting in possible damage to your racks and your freezer. Excessive bowing can also hinder smooth retrieval of your samples. | ||
| Proper freezer maintenance is essential for optimum performance. Contact your freezer manufacturer for maintenance procedures. | ||
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What Is The Advantage Of Using A Locking Rod?
| Upright Rack | Chest Racks |
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Other methods have been used for preventing boxes from sliding out of freezer racks. One method is a small vertical metal lip (1/4-inch) on the front of the rack shelf. Boxes can easily slide into the shelf, drop down over the lip and be prevented from sliding out. The disadvantage of this method is in having to lift the box high enough to clear the lip. The spacing of the rack around the box does not allow a person’s fingers to easily grab the box.
Another method is a thin wire attached to the front metal “runners” and fastened to the shelves. The wire is raised to allow access to the boxes or lowered to prevent the boxes from falling out. The thin wires are bent and fastened in place to small holes in the “runners”. The disadvantage of this method is that the small wires tend to catch on other racks in the freezer.
A locking rod is used on a freezer rack to protect the boxes that are stored in the rack from falling out. When removing racks from liquid nitrogen freezers or -80º C mechanical freezers, there is a tendency to tilt the top of the rack forward. Without a locking rod, some or all of the boxes could slide out of the rack, causing scattered and damaged vials
Custom Biogenic Systems recommends the locking rod option as the preferred method of protecting your boxes.
What is a "LARGE" Box and What Cell Divider Will It Hold?
A large cardboard box has dimensions of 5 ¾” x 5 ¾”. A large stainless steel or aluminum box has dimensions of 5 5/8” x 5 5/8”. The group of large boxes, cardboard, stainless steel and aluminum, are available in 2” and 3” heights. There are four dividers that fit large boxes as follows:
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Part Number |
Divider Name |
Cell Capacity |
Cell Opening |
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D100L |
100 Cell Large |
100 |
0.50” |
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D64L |
64 Cell Large |
64 |
0.66” |
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D36L |
15 mL Tube Divider |
36 |
0.875” |
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D16L |
50 mL Tube Divider |
16 |
1.375” |
The 3” height cardboard boxes can be used as a 3.75” height box by having the lid slide upwards, or telescope, to meet the vials height, as would be required when using 5.0 mL vials. Also, 3” height cardboard boxes that are used to store 15 and 50 mL tubes will have the lid slide upwards to 4 ¾” to meet the height of the tubes.
| D36L |
D16L |
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What are the Advantages of a Plastic Box Versus a Cardboard Box, Including Weight Difference?
PLASTIC BOXES
» Plastic boxes are sturdy and will seldom need to be replaced.
» Plastic boxes have numbered cells so product that is stored is easy to locate.
» Plastic boxes have builit-in dividers.
CARDBOARD BOXES
» The freezing environment can damage cardboard boxes. Snow, created by the cold, can attach
to the box and melt when the box is removed from the freezer. If melting snow does occur,
the water wil weaken the cardboard. Damaged cardboard boxes must be replaced.
» Cardboard boxes do not have numbered cells, reducing ease of product location.
» Dividers must be purchased for cardboard boxes.
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WEIGHT DIFFERENCES
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| Plastic | Cardboard | |
| Aluminum rack with 13 shelves loaded with boxes | 7.8 lb | 5.4 lb |
| Aluminum rack with 13 shelves loaded with boxes and 1300 vials containing cells and media and placed into an LN2 immersion freezer | 20.3 lb | 17.9 lb |
| Aluminum rack with 13 shelves loaded with boxes and 1300 vials containing cells and media and placed into an LN2 vapor storage freezer |
What are the Standard Vial Sizes and What Box/Divider Will They Fit Into?
The most common vials are used for cryogenic storage. Vials have different types of caps, externally threaded and internally threaded. The cap of an externally threaded vial will be larger than the vial body and will require more room for storage. The cap of an internally threaded vial will be the same size as the vial body and will require less room for storage. Vials are available for their working volume and length as follows:
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THREADS
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WORKING
VOLUME |
LENGTH
(INCLUDING CAP) |
REQUIRED BOX
HEIGHT |
PROPER BOX
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PROPER DIVIDER
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| Internal | 1.0 mL | 42mm / 1.65" |
2"
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B2CS | D100S |
| Internal | 1.8 mL | 49mm / 1.93" |
2"
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B2CS | D100S |
| Internal | 3.6 mL | 70mm / 2.8 " |
3"
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B3CS* | D100S |
| Internal | 4.5 mL | 92mm / 3.6 " |
3.75"
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B3CS* | D100S |
| External | 1.0 mL | 41mm / 1.61" |
2"
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B2C | D81 |
| External | 1.8 mL | 48mm / 1.89" |
2"
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B2C | D81 |
| External | 4.5mL | 91mm / 3.58" |
3.75"
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B3C* | D81 |
| * The B3CS and B3C box will telescope up to accommodate the taller vials. | |||||
What is the Difference Between
Standard and Waterproof Cryogloves?
Both standard and waterproof cryogloves provide protection from -160°C (-250°F).
Standard cryogloves provide protection when working with a closed cryogenic system, when there is little or no risk of exposure to cryogenic fluids.
Waterproof cryogloves should be used when handling liquid nitrogen to protect against splashes. Gloves should be loose fitting with adequate cuff length to protect as much of the arm as possible.
NO GLOVE, WATERPROOF OR STANDARD, IS RECOMMENDED FOR IMMERSION IN LIQUID NITROGEN.
What is a Standard Box and What Divider Will it Hold?
A “standard” box is made from cardboard, plastic, stainless steel or aluminum. The outside dimensions of standard cardboard and plastic boxes are 5 ¼” x 5 ¼”. The outside dimensions for stainless steel and aluminum boxes are 5” x 5”. Standard size boxes are primarily made to hold cryogenic vials. Eighty-one (81) of the 1.0 mL and 2.0 mL vials will fit into 2-inch high standard boxes. Eighty-one (81) of the 4.0 mL and 5.0 mL vials will fit into 3-inch high standard boxes. The 5.0 mL vial will raise the lid of a standard 3-inch high cardboard box to 3.75-inches. There is also a standard size plastic box that is tall enough to accommodate a 5.0 mL vial. Standard plastic boxes can hold (81) or (100) vials depending on the caps on the vials.
Vials have different types of caps. With an external thread on the vial, the cap will be larger than the vial body and will require more room for storage. The externally threaded vials will require 81-cell dividers. Vials with internal threads have the same body and cap size and will fit into a 100-cell divider.
Custom Biogenic Systems makes cell dividers for a number of sizes other than the most popular 81-cell and 100-cell sizes. Visit CBSfreezerracks: DIVIDERS to view our complete line of cell dividers.
Why Are My Cardboard Boxes Damaged?
Boxes that are made from cardboard with litho paper coating are the most likely boxes that will be damaged. Boxes are stored in freezers at temperatures from -20°C, -80°C and -196°C. Metal racks made from aluminum and stainless steel are also used to store the boxes. When racks are removed from storage freezers, moisture in the atmosphere will attach to the rack as ice crystals. The ice crystals can fall from the rack and land on the boxes when the racks and boxes are moved in and out of the freezer. Room temperature of 70°F (21°C) can quickly warm the ice crystal and thaw it into water. Water will soak into the cardboard material, soften it and weaken the cardboard.
CBSfreezerracks.com offers several varieties of boxes that can reduce or even eliminate the problem of water damage to your freezer boxes. Our new Moisture Resistant Polyguard cardboard box will reduce damage by resisting water absorption into the cardboard. Our complete line of aluminum, stainless steel and plastic boxes will virtually eliminate water damage.
