The capacity printed on a cryogenic tank's datasheet is a theoretical figure. What actually fits is decided by the furnishing system — racks, cryogenic cassettes and box systems — and by which positions remain usable in day-to-day operation.
The difference is substantial. Two identical tanks can differ by more than a third in genuinely usable capacity, purely through the choice of furnishing system. For biobanks that means one thing: before buying another tank, it is worth checking whether the existing ones are furnished correctly.
Four factors sit between theoretical and usable capacity:
Account for those four in planning and you arrive at a dependable number. Read only the datasheet and you plan past reality.
Racks carry the boxes and define the vertical structure. What matters:
Consarctic® supplies standard racks as well as custom-engineered storage towers and special designs, dimensioned for the specific tank model and sample format in use.
Cassettes are the most efficient format for straws and bags. They hold more units per unit volume than boxes and allow a lower build height — which translates directly into the number of levels available.
In reproductive medicine, cassette systems are standard because they hold straws in their native format without repackaging. In cell therapy, the same applies to cryobags.
Boxes are the flexible standard format for cryovials. The decisive variables are grid format (typically 25, 81 or 100 positions) and build height. Two practical rules:
Denser storage is only a gain if sample quality does not suffer. The critical parameter is retrieval time: the longer a rack is withdrawn from the cold zone, the more every sample in it warms — along with a portion of the neighbouring positions.
Three design answers:
Denser storage, shorter retrieval times and lower consumption are, when specified correctly, the same outcome.
For long-term storage, Consarctic® supplies the BSD+ series (scalable to 100,000 cryovials) and the BSF+ series (up to 1,700 × 500 ml bags) for biobanking, stem cells and pharma. For reproductive medicine and general laboratory use, the ABV+ series (aluminium, 4–150 litres, for vials, bags and straws) and the ABS+ series (stainless steel) are available.
Specification is delivered as a planning service; commissioning includes IQ/OQ qualification with temperature mapping and GMP-compliant documentation to EN ISO 13485:2016 and ISO 9001:2015. Biobanks including Qatar Biobank and the German Red Cross work to this methodology.
Consarctic® systems scale to 100,000 cryovials (BSD+ series) or 1,700 × 500 ml bags (BSF+ series). Genuinely usable capacity depends on the furnishing system, sample format, temperature gradient and an operating reserve of roughly 10–15 %.
By optimising the furnishing: a single uniform box format, lower box heights to gain additional levels, cassette systems for straws and bags, and a tank design with a flat temperature gradient that makes upper positions safely usable. This frequently unlocks more than 20 % additional capacity.
Cryogenic boxes are grid containers for cryovials, typically with 25, 81 or 100 positions. Cryogenic cassettes are flat carrier systems for straws and bags that hold them in their native format and fit more units per unit volume. Boxes are standard for vials, cassettes for straws and bags.
Because vapor phase storage only releases positions that stay permanently below –130 °C, because racks require access clearance, because mixed sample formats cost volume, and because an operating reserve of 10–15 % is needed to manage the inventory.
For a uniform, stable sample format and larger holdings, generally yes. Custom storage towers exploit the tank geometry fully and avoid the waste inherent in standard formats. Consarctic® engineers racks and cassettes on request to match the tank model and sample format.
Before procuring an additional cryogenic tank, review the furnishing of the ones you already have. Box format, rack geometry, temperature gradient and retrieval process together decide how many samples a tank can genuinely hold safely.
Hitting capacity limits, or planning an expansion? Consarctic GmbH analyses your inventory, specifies matching racks and cassettes, and qualifies the expanded configuration. Get in touch.