As states continue to expand public testing for COVID-19 there is an increased demand for cold storage to hold sample tubes while they wait in line for Coronavirus testing.
Viral transport media has an average shelf life of one year but the moment a patient sample has been added it must be stored at 4C if the testing will be done relatively soon, or cryogenically frozen if the backlog is significant.
While it has always been imperative to protect patient samples, the mad rush on sterile plastic transport tubes pushed less than ideal transport tube alternatives into the market and has made sample security an even higher priority.
For example: 15mL conical tubes, commonly used for basic mixing and storage of cells and other lab media, are being stuffed into biohazard bags and shipped by air in unpressurized cabins causing them to crack or pop open.
How to properly protect a COVID-19 sample from the time it has been collected through processing is beyond the scope of this article, instead we want to focus specifically on how to store them in the refrigerator or ultra-low temperature freezer.
There are three specific laboratory freezer racks that are ideal for storing viral transport media tubes depending on the tube and capacity.
A COVID-19 testing center using 15mL tubes has two options for storing their viral transport media tubes.
This one is familiar to anyone who has worked in a lab because samples are stored and organized in cardboard or plastic cryo boxes.
These freezer racks are available in configurations that hold four, six or eight freezer boxes and offer a maximum capacity of 288 tubes.
Storing viral transport media inside a box can be helpful for organizing samples based on testing center and/or specific days.
The COVID-19 testing lab technician can make notations on the box to identify the contents.
The alternative freezer rack for 15mL transport tubes have a very different design.
These laboratory freezer racks feature pull-out drawers and trays fitted with expanding plastic rings to hold each tube separate and secure.
These are especially valuable where it is important to keep samples apart and reduce the chance for cross contamination.
Like all freezer racks with drawers, the additional steel used in construction makes them quite heavy to lift.
However, once the freezer rack has been fitted in place it is very easy to access the contents by simply sliding out the drawer.
Each freezer rack drawer has a slot on the front of the drawer for inserting an identification card; similar to a library card catalog (for those old enough to remember those!)
Note: If you spot ectoplasm, turn and run! (Any Ghostbusters fans?)
The capacity is smaller, only 208 total tubes fit into the largest drawer freezer rack, but these could be ideal for organizing a larger number of patient samples when sorted based on specific drawers instead of individual boxes.
And for the COVID-19 testing center that uses the more traditional sized 3-10mL transport tube, there is a version of the freezer rack drawer made especially for tubes of this size.
This laboratory freezer rack is called a “blood tube” freezer rack and comes in a range of sizes that match the traditional volumes used when drawing and storing blood samples.
The maximum storage capacity for these blood tube freezer racks is 230 total samples.
The expanding plastic rings might require effort inserting and removing standing tubes with a flanged base but will pose no problem for round bottom or slim transport tubes.
If you are running low on freezer space, Stellar Scientific can help your lab expand with an energy efficient and affordable ULT -80 freezer too.
Stellar Scientific is your cold storage expert for COVID-19 testing.