Pickled weasels and elephant foetuses: museum relies on the 'urghh factor'

The air is lightly perfumed with fishy methylated spirit as rows of exotic beasts – from an egg-laying hedgehog to an aquatic dinosaur – stretch out in a line of giant pickle jars.

It may sound like the latest ghoulish Brit Art sensation but it is in fact a manifestation of attempts to make the nation's museum collections, and workers, more accessible to the public.

The Natural History Museum opened its £30m Darwin Centre yesterday in a space-age building in South Kensington which houses 22 million preserved animal specimens. The museum attracts nearly two million visitors a year and from Monday they will be able to tour 17 miles of newly arranged shelving that holds 450,000 glass vessels containing creatures collected from around the globe in the past 300 years.

Drawing unashamedly on what museum chiefs call the "urghh factor", the entrance is lined with receptacles holding items from the head of an elephant foetus to 70 marinating mice. But rather than being a showcase for freakish zoological exotica culled by generations of colonial explorers, the museum insisted the philosophy behind its makeover was thoroughly modern.

Sir Neil Chalmers, the director of the museum, said: "This is a collection which has never been put on display before and yet all the time it is used by researchers and scientists, who in turn will be explaining their work to the public. In an era where understanding our environment becomes ever more important, the research projects we do here, for example being able to test water purity, are hugely important."

The centrepiece of the collection, which ranges from pickled weasels to a petrified Komodo dragon, is a basement containing 50 steel vats holding the museum's largest creatures. Floating in a mixture of ethanol and methanol the colour of stewed tea, one containerheld a 6ft tuna, a 50-year-old giant stingray and a coelacanth, the sole surviving species of prehistoric fish.

Along all four walls of the room were metre-high jars containing a frozen menagerie of snakes, baby crocodiles and finds collected during Captain Cook's first voyage to Australia in the 1770s.

The collection forms one of the largest "libraries" of the natural world for use by the museum's 350 researchers and scientists. The collection was moved from a 1920s building, known as the Spirit Building, which had become a fire hazard and has been demolished.

A second phase to the Darwin Centre, to house the remaining 34 million items in the museum's plant and insect collection, is due to open in 2007.

As part of its reinvigorated mission to explain, the Darwin Centre will host twice daily sessions by two of its scientists to explain their work, aided by satellite and internet links.

For some, it is a rare opportunity to explain a life's work. Breaking off from a presentation on the first barracuda to be found in British waters, Oliver Crimmen, the curator of fish, said: "We have been in the basement for years. Now we are very much in the open."