From Laboratory Asset to Maintenance Liability.

The -80.C freezer is such a ubiquitous and familiar item of equipment in most life science laboratories we often forget it is there. It’s an important, and expensive, research asset – storing reagents and biological samples at all stages of the experimental life cycle. Many freezers are “transactional” with items going in and out all the time, while others sit quietly at the back of laboratories guarding precious collections of samples and reagents, rarely being bothered by activities in the laboratory.

But while these cold stores are often essential assets to research, they can become significant liabilities. Many freezers are filled with sample collections that are put there because they can not be destroyed; an important collection of vectors, a library of antisense RNA oligos, cell cultures that were the basis of that landmark publication in Nature a few years ago. In short, important resource that may have required a significant investment in time and money to create. The value of an original sample may escalate as more data accumulates – perhaps they were genotyped but have since been whole genome sequenced. RNAseq or proteomic assays may have revealed new insights. Samples can become important scientific assets into which large amounts of money have been invested.

Important biological collections may need to be preserved for years, perhaps decades. They need stable storage conditions to maintain maximal viability so that when that transformative new analytical technique comes along, a whole new field of research opportunities may open up for a well-preserved sample collection. But regular temperature fluctuations as freezer doors are opened and closed many times each day can lead to sample degradation by small degrees. Over an extended period, degradation can become significant which may ultimately compromise their potential use in future experiments.

Many sample collections turn from scientific asset to maintenance liability. As freezers fill up (as they always seem to do) they begin to consume valuable space in the laboratory. Old freezers are energy hungry and can consume up to twice as much power compared to when they were new. There also comes the concern about what would happen if the freezer broke down? Is there a ‘plan B’ for those important samples?

Added to integrity concerns may be more significant ones regarding the origin of samples themselves. Who owns the samples in the freezer? Are the tubes suitable for long term archival storage? What about those handwritten labels on coloured tape – were they ever barcoded? Who has the manifests that details the contents? Is there a manifest? And then the killer question – is any of the material in the freezer relevant under the Human Tissue Act? Is the ethics approval on file and still up to date?

All of this begs the question – have -80.C freezers had their day? Is there a better, more energy efficient option that not only safely stores samples, but also protects their integrity, visibility and traceability for as long a lifetime as required? While -80.C freezers may be convenient, they have serious limitations for preserving large-scale or long-term sample collections.

The good news is that yes, there is a better option. Storing samples in automated cold stores has many significant advantages over the stand-alone -80.C freezer.

What really makes automated cold stores stand out compared to manual freezers is their ability to maintain exceptionally consistent temperatures - high store thermal mass ensures minimal temperature fluctuations and maximum sample integrity over very long storage terms. This, combined with samples stored in individual 0.9ml aliquots, makes samples accessible without damaging freeze/thaw cycles for the entire sample.

Equally important is the ability to track and trace samples. One and 2-D barcoded sample tubes allow for fully automated tracking, placement and retrieval. Full cold store and laboratory LIMs integration ensures rapid transfer of samples into laboratory processing workflows while full inventory control ensures sample collections can be managed with confidence and meet ethical and HTA requirements.

Access to samples needs to be timely and efficient and again automated storage excels here. Fully automated, temperature-controlled loading and picking is achieved using rapid, high volume, sample picking robots which are capable of retrieving many thousands of individual samples each day. Automated sample picking can also be designed to custom layout/configurations, with options available for blind/anonymised picks which can be very helpful if the study design stipulates this.

Another notable benefit to automated cold stores is their energy efficiency compared to manual storage. Cold stores outsource direct emissions, reduce indirect emissions and have a far superior cooling efficiency than older freezers. High speed sample reformatting allows routine defragmentation of space to maximize efficient storage whilst high density sample storage ensures very efficient use of refrigerated space. All of this works to minimise the carbon footprint of each sample which is not only important to a global sustainability agenda but is also becoming a critical factor for study design, especially during a grant application process.

So, if automated cold stores are the future for biospecimen storage, how can researchers make the transition from manual storage given that moving and cataloguing large sample collections can be a daunting task?

The first step is to determine exactly what samples you have, and who is looking after them. Once you’ve identified where your samples are stored, reach out to your Storage provider who will be able to provide a recommendation to work with you to move your collection to automated storage.

If your research project is still in the discussion phase, taking the time at the very first stages of your planning process to think about your sample journey – from collection to final resting place - is key. It is unfortunately quite common for the focus during study design to be on the upfront funding requirements and the final scientific output without giving due consideration to the protection and integrity of the samples along the way. Success lies in working closely with your storage partner during the initial planning stages of the research, building automated storage into the plan from the start, and factoring in the costs of the storage into all funding and budgetary discussions and commitments.

Which brings us finally to the ‘elephant in the room’ – isn’t automated storage more expensive than manual storage? Whilst the quick answer is ‘yes there is an additional cost’, this is just a short-term view. If automated cold stores are factored into the budget right from the start, the incremental cost spread across the duration of the study is not significant – and the benefits are compelling. It is also worth noting that the cost of a lifecycle of a manual freezer (5 years) is the same as the cost of an automated storage for the same period in a cold store that will last for many years.

So, is what was once a Laboratory Asset, now more of a liability? Whilst there may be an additional short-term cost for using automated storage, is it time to consider that the many benefits, and the guaranteed HTA compliance, far outweigh this cost differential?

Tony Cox OBE is CEO of UK Biocentre, a respected leader in sample management, high-capacity bioprocessing and the UK’s leading provider of large-scale sample storage services. With a fully automated infrastructure supporting storage of 30 million samples, UK Biocentre understands the importance of preserving samples and hosts many internationally important sample collections. UK Biocentre provides a full sample collection and management service and can collect, catalogue, inventory, reformat, relabel and store a sample collection. As part of the inventory process, ethics and HTA compliance requirements are certified giving complete reassurance that samples meet any applicable regulatory regulations. Samples will transfer to 2D-barcoded, high-quality screw-cap tubes which will be loaded into fully automated storage, giving a complete inventory that offers the ability to exploit the full potential of any sample collection. [For those UK Biocentre clients who already have a collection stored in manual freezers, UK Biocentre will cover the cost of re-formatting these samples]. Retrieving samples is as simple as submitting a picking list and samples will be retrieved – free of charge - and couriered by return meaning samples can be with a customer within 24 hours of receiving a picking request.