Transwab® was the world’s first sterile disposable ready-to-use transport swab kit, providing a simple and reliable method of transporting microbiological specimens from patient to laboratory. Today it remains a world leader in specimen transport, suitable for all kinds of microorganisms and fully compliant with medical devices regulations and technical standards.  
  
Although microbes can be virulent and dangerous, they can be difficult to transport effectively. Often they will die off altogether and be undetectable when the specimen reaches the laboratory. Or if the material sampled contains several types of microorganism, these may compete while in transit so that the specimen received by the laboratory is not a true representation of the patient’s condition. This has always been a problem, but has become even more significant with the centralisation of laboratories. Specimens may have considerable distances to travel and be in transit for long periods.
 
In 1946 Stuart introduced a method for transporting samples containing Neisseria gonnorhoeae. Users were provided with small glass vials filled to the brim with his new formulation of transport medium, sterilised by autoclaving. Also provided were woodstick applicator swabs with charcoal coated cotton buds. The specimen was taken with the swab, and the bud snapped into the vial which could then be despatched to a laboratory.

Although successful, it was found to be less suitable for other specimens because some bacteria can metabolise certain constituents in the medium. The glass vials had to be washed and were not always effective in preventing oxidation of the medium if stored for more than a few weeks. The charcoal coated buds were not popular with patients, and the process of snapping the wood stick swabs could be hazardous.
 
In 1967 Amies introduced a medium containing charcoal. This new formulation also avoided the problem of a nutrient contributing to the overgrowth of interfering organisms. The medium was semi-solid, with agar included to improve the conditions for anaerobes. 
 
In 1975 Medical Wire launched Transwab®, a complete sterile ready-to-use product with swab and a swab-length tube of semi-solid transport medium, based on Amies’ formulation. There was no need to break the swab into a glass vial, there was no ampoule of medium to crush, and the product could be stored for at least two years without deterioration. It had been shown that both wood and natural cotton wool contain fatty acids which can be toxic to many bacteria, and this can be exacerbated by the irradiation used to sterilise many medical devices, and so Transwab® included a plastic shaft swab with synthetic fibre bud. In recent years the bud material has been changed to rayon, a form of cellulose which is now recognised as the optimum fibre for the transport of live specimens.

Over the years, Transwab® has led the way with innovations such as the Bell Cap incorporating a double seal for secure containment of specimen, and enhanced safety for users. A range of shafts was introduced, including standard plastic, straight wire aluminium with a narrow bud for urethral specimens, and flexible twisted stainless nichrome for urethral or pernasal specimens. The shafts are readily identified by colour coded caps. Users now have a choice of media, ranging from the original semi-solid medium with or without charcoal, liquid medium (Transtube®), and Cary Blair Medium which is recommended for rectal specimens. Easy-to-open peel pouch packaging was introduced for the convenience of users.

Since1995 Transwab® have been CE-marked as Class IIa devices in accordance with the European Medical Devices Directive. This provides assurance to users that devices are safe and fit for their intended purpose.

In 2004 the NCCLS standard M40-A was published, providing criteria for the performance testing of microbiological transport devices. Medical Wire was involved in the development of this standard and had already incorporated its provisions into its quality assurance programme for Transwab® in 2001.