Long Term Sample Storage at the LifeLines Project

Jacko Duker,Procesmanager,LifeStore,Bloemsingel 1,9713 BZ,Groningen,The Netherlands.

In Biobanking, sample security is of paramount importance. Thousands of potentially irreplaceable samples may be kept over several years for use in research, and it is vital to know that storage systems accurately maintain the required temperature and are reliable enough to keep them safe. At the LifeLines project in the Dutch province of Groningen, this need is keenly understood and the team has selected its storage systems with great care.

The LifeLines project

The LifeLines project was set up in 2006 with the aim of becoming a large scale genetic study lasting for 30 years and including around 165,000 participants spanning three generations, each providing researchers with biologic samples for analysis. The project’s main aim is to investigate why some people remain healthy and active throughout their lives while others become disabled at a relatively early age. Particular attention is being paid to chronic illnesses such as diabetes, kidney failure and asthma. In order to develop a clear understanding of how and why these develop, the LifeLines project examines a range of factors that contribute to a person’s general health and risk of developing chronic diseases.

Results and information gathered during the LifeLines project is expected to enable the development of indivisualized prevention and treatment programs. Chronic illnesses tend to follow a pathway, and if they can be detected and defined at an earlier stage there is the potential to save the healthcare system time and money, as well as to dramatically increase the comfort of the patient.

The research conducted at the LifeLines project has already been making an impact, having been included in several publications.

The LifeLines project image
Selection of sample storage equipment for the LifeLines project

Overall, the LifeLines project expects to hold a total of 8 million 1.4 mL 2D-coded sample tubes (Matrix and FluidX). Depending on the health of the participant, 50% of these samples may be held for the entire duration of the project, and so reliability of the storage equipment is crucial.

Initially, up to 100 freezers were needed before the samples will move to the Bios, the robotic -80 freezer, and all equipment had to meet strictly defined standards. Temperature stability was particularly important to the researcher, as experience had shown that some freezer models exhibited temperature gradients from the top to the bottom of the freezer, or heat leakage from around the door.

During the selection process, products from four freezer manufacturers were tested to see how well they met the specifications. The evaluations included temperature tests on 3 to 4 different spots inside each freezer compartment, based on a specified temperature of approximately -81°C with a maximum accepted temperature deviation of -7°C between the coldest and warmest spot within the internal chamber.

Freezers then underwent stress tests, where the doors were opened for 1 minute, closed again for 30 seconds and then checked to see how well they held and recovered their programmed temperatures. As the freezers were likely to be opened and closed on a regular basis to access the samples, it was crucial they didn’t warm up too much or take too long to stabilize.

Finally, power consumption was monitored over 7 days to ensure energy efficiency.

After testing was complete, Panasonic ultra-low temperature (ULT) freezers were selected for the Lifelines project after demonstrating their ability to easily achieve the required standards in price, quality and temperature stability.

Cost efficiency with long-term storage solutions

Panasonic was the first company to introduce vacuum insulation panels in its ULT freezers. The range typically provides 25% more storage capacity for a given floor area, saving valuable laboratory space and running costs in institutions such as the Lifelines project, where multiple freezers are required.

Freezer technologies ensuring sample security

Advanced microprocessor controls in the freezers selected for the project constantly monitor function, including system and ambient conditions, for reliable operation. With comprehensive set point, alarm, monitoring and diagnostic functions continuously taking place, every aspect of the freezer environment is checked on a regular basis to ensure samples remain secure.

High temperature warning equipment indicates when the temperature inside the freezers deviates ±10°C from the set temperature. A power failure alarm lamp and buzzer will activate in the event of power outage or irregular temperature increase. An additional alarm and temperature monitoring system was also able to be installed at the LifeLines facility, giving a second layer of security to the stored samples.

Since the purchase of the freezer system by the LifeLines project, an updated model has been produced by Panasonic. This latest model incorporates a Twin Guard Dual Cooling system, specifically designed to provide the highest possible security. Having two individually controlled compressors not only maintains an ultra-low temperature within the freezer chamber, but also means that should there be a problem with one compressor, the second will maintain a working freezer temperature of -70°C until service is arranged.

Valuable contributions to biobanking

The success of the investigations carried out in Biobanking facilities depends on the samples being maintained in optimum condition. At the LifeLines project, the Panasonic freezer system is used for preserving the samples from thousands of participants while still maintaining the units? lowest possible energy consumption. To ensure viability, each and every sample is kept in a stable, reliable environment, and is constantly monitored to ensure that optimum temperatures are maintained over many years.

Valuable contributions to biobanking image