Samples are viewed by many as one of the most valuable assets of a laboratory. The costs inherent in storing samples for short or long periods of time is very high taking into account that you need the personel, equipment and logistics needed to organize your sample storage. Securing the integrity of you sample is one of the most important goals of effective storage.
The Sample Storage market has developed rapidly over the last 10-15 years enabling delivery of more reliable and faster methods of storing and screening your samples. Before the advent of 2D coded tubes, most Compound/Freezer stores and Screening departments were using fixed plates, non-coded tubes or tubes pre-labelled with a linear barcode on the side of a tube to store samples.
In the case of a fixed plate with a barcode, the risk of interchanging a tube was small as long as the label stayed on the plate. The biggest disadvantage of fixed plates is that the format they offer is not flexible enough for retrieving individual samples for further processing – a common demand of modern storage and screening.
Loose non-coded tubes gave users the flexibility they required in their processes, but did not solve the problem of unambiguously tracking and tracing the sample during the process and for its correct retrieval from storage.
Consequently users started putting labels on the side of their tubes. As long as the labels stayed on, the problem of traceability was solved, but this extra manual labelling step drastically decreased throughput compared to the other systems.
In 2000, Micronic BV introduced a novel 96 well 2D coded tube system that offered that offered a unique code laser-encrypted into the plastic bottom of the tube. With this unique and durable coding system, all the above mentioned problems were solved in one go.
The secure sample traceability issue was solved by permanently encrypting a 2D code in to the bottom of each tube. Flexibility was ensured, as the developed system was based upon an array of loose tubes in a 96 well tube holder. Additionally throughput was greatly improved compared to other systems, as all 96 well tubes could be read in a single scan within 1.5 seconds.
The laser encrypted Micronic 2D code started the second generation of traditional linear barcodes. The 2D code provided a much higher capacity than the traditional linear barcode, as more data could be stored in a much smaller surface.
Today there are two different 2D tube coding systems available on the market: The Datamatrix code:
an open source square code offering containing 10 billion permutations. The Micronic TraXis code:
a proprietary code built up of hexagonal dots etched onto the round tube bottom and giving a 100%, world-wide, present and future uniqueness.
How tubes are used today ...
Today 2D coded tubes and systems are being increasingly implemented at all levels and in most areas of the highly sample regulated Life Science market. From large Pharmaceutical companies with huge automated compound stores to the smaller specialised life science labs manually handling samples - 2D coding systems provide secure traceable sample storage and retrieval.
Choosing your traceable sample storage solution
Not all 2D coded sample storage tubes, even those using the same coding system, are the same. It is critical that the sample you place into long term storage is completely unaffected by the storage process. Consequently criteria to consider when selecting your traceable sample storage solution should include:
Purity of the tube plastic: for effective long-term storage it is of the utmost importance to eliminate the possibility of extractables leaching from the tube plastic into your sample. Using only tubes made from high purity grade polymers in certified clean production environments maximises long term sample integrity in storage tubes.
Quality & Flexibility of the tube seal: during longer-term storage, some samples, especially those in solution (e.g., DMSO), will attract water so that it will become diluted. A perfect sealing of the tube will prevent this.
Robustness of tube coding:
samples stored over long periods of time are often subject to repeated handling, freeze-thaw cycles and aggressive solvents. To ensure long term integrity requires a code that is permanently encrypted into the plastic bottom of the tube. Such a code will ensure the safe retrieval of your sample even after long- term.
Freeze and thaw cycles can influence the quality of your sample. In such cases, storing lower volumes can help you to upkeep the quality of your sample.
Ultraviolet light can also have a negative influence on your sample. In cases where you are not sure if your samples are light-sensitive –black storage tubes are the safest solution.
Driven by increasing sample numbers and the need to drive down the cost of storage the demand for smaller size tubes that take less space to store will increase. This is already evidenced by the recent launches of new 0.65ml and 0.35ml coded tubes in a 96 well format and a 384 well non-coded tube system.
However, like the trend for denser format microtitre plates, new automated handling systems to handle the new formats will be a rate determining factor in the development and adoption of the next generation of smaller size storage tubes.
Increasingly customers are looking for traceable sample storage solutions optimised to ensuring the integrity of samples under different circumstances such as black tubes for light sensitive samples and screw top tubes to guarantee sample integrity of samples stored at -180ºC
In some industries, e.g. food and veterinary science, sample sizes are typically larger, consequently higher volume tubes (2.5 ml) that still offer the convenience of working in the standard 96 well format are being developed. For storage of samples in more aggressive solvents a new generation of 2D coded glass tubes that can be stored in a 96-well format are now available.
New specialised coded tube racks now offer improved certainty of sample positioning / allocation and compatibility with automated systems
The 2D coded tube offers an increasingly wide array of secure traceable sample storage solutions that are being adopted in industries including pharmaceuticals, biotechnology, clinical diagnostics, veterinary science and food and beverages. The sample security that 2D coded tubes provide is today universally accepted and welcomed in the market, although there are more considerations than just traceability. The latest development in 2D coded tube systems that combine flexibility, traceability and ensure the integrity of your precious samples are truly moving towards the ideal sample storage solution.