At Sigut Labs, many of the compounds we produce (nucleotides along with other sensitive biomolecules) are highly temperature-dependent. Their molecular integrity can degrade if they spend too long above their required storage temperature, and once that integrity is lost, so is the reliability of any lab work that depends on them. That’s why we treat cold-chain shipping as a core part of the product, not an afterthought. The single most important tool in that process is dry ice.

Why dry ice

Dry ice is solid carbon dioxide, and it sublimates at −78.5 °C (−109.3 °F), passing directly from solid to gas without leaving any liquid residue behind. That gives us two things at once: an extremely low, stable temperature, and a clean, dry environment inside the package. For nucleotides and similar compounds, that consistently low temperature is exactly what prevents the gradual breakdown of sensitive molecules during transit.

It also protects against one of the quieter threats in shipping: freeze-thaw cycling. Repeated warming and refreezing can cause both mechanical and biochemical damage to a sample, and the damage isn’t always visible. By keeping our shipments solidly frozen from the moment they leave us until they reach your bench, dry ice keeps the material in a single, stable state the whole way through — which is what makes the results you get from it reproducible.

Dry ice holds these temperatures for extended periods, too, which matters for longer routes and international destinations where transit time is harder to predict. Even if a shipment runs into an unexpected delay, there’s enough thermal margin built in to keep the contents safe. A good example: we successfully shipped to New Zealand — about as far as a package can travel — packed with 8 kg of dry ice, and it arrived two weeks later still with dry ice to spare. That margin is exactly what lets us ship with confidence to nearly anywhere in the world.

How we pack

Every temperature-sensitive shipment is packed with enough dry ice to comfortably outlast the expected transit time, with margin to spare. We use insulated containers designed to slow sublimation and hold the cold, and we package and label everything in line with the regulations governing dry ice and biological materials in transit (UN 1845), so each shipment moves safely and legally. The photos below show what our packaging looks like at each stage.

For clients who require documented proof of cold-chain integrity, we can include temperature data loggers in any shipment on request, giving you a full temperature history from dispatch to delivery for your QC or audit records.

When and how we ship

We typically send temperature-sensitive compounds on Mondays (to our clients in America or Asia). Shipping early in the week gives the package the maximum number of business days to clear any customs checks and complete its journey before the weekend when handling slows down and parcels can sit in transit. In practice, this means our shipments usually clear customs without delay and arrive directly to you within the same week (typically Wednesday or Thursday). For our EU clients, timing is more flexible — because shipments within the EU typically arrive the next day, we can dispatch any day of the week without risk of a package sitting in transit over the weekend.

On customs, we do everything we can to make clearance smooth. We provide all relevant shipping and customs documentation ahead of each shipment, and we’re happy to work closely with you to make sure everything is in order before the package leaves us. That said, customs clearance itself rests with the client or their appointed broker. SigutLabs cannot be held responsible for significant delays that occur during customs — for example, where required information or cooperation with the relevant authorities is not provided on the receiving end. The smoothest clearances happen when documentation is reviewed and any local requirements are confirmed in advance, and we’re glad to help you prepare for that.

Our default carrier is DHL, which we’ve found dependable for cold-chain international freight. That said, we’re flexible — based on a client’s preference we can also ship with FedEx or other specialized cold-chain vendors to suit your logistics and receiving requirements.

It’s a small set of choices — generous dry ice margins, careful packing, early-week dispatch, and the right carrier — but together they’re a reliable way to make sure what arrives at your door is in exactly the condition it left ours.

If you have questions about how we ship to your location, or about handling and storage once a shipment arrives, get in touch — we’re happy to walk through the details.