The Development History Of Specimen Collection
1948: Stuart's Medium
In 1948, Dr. R.D. Stuart and co-workers efforts led to the introduction of medium what is known today as Stuart's medium. It consisted of Sodium Thioglycolate, Sodium Glycerophosphate, Calcium Chloride and Methylene Blue as a color indicator. And it’s for maintaining the viability of organisms while in transit using a swab as a collecting device for the first time. Two decades later Cary and Blair modified Stuart's medium by replacing Sodium Glycerophosphate with inorganic phosphate and raised the pH to 8.4.
1967: Amies Medium
In 1967, Dr. Amies confirmed Cary and Blair's finding and further modified the Stuart's formula by eliminating Methylene Blue and adding inorganic phosphate salts as buffering agents and charcoal. These modifications resulted in higher percentage of positive cultures, especially in samples containing fastidious organisms such as Neisseria gonorrhoeae.
Stuart's and Amies transport swabs have since been the most popular and commonly used transport systems for a wide range of clinically significant microorganisms while Cary and Blair's medium supported the viability of the enteric pathogens in fecal samples.Today these transport media remain the preferred choice even though little change in formulation has occurred during the past several decades.
Development of Swab Technology
However, the swab collection devices, which are the critical component of any transport system, have continuously evolved and gone through multiple technological advancements in design, materials and performance characteristics to the point that no longer one swab fits for all purposes.
1990: Media-Free Transport Systems (Elution Swabs)
In 1990, a foam swab for media-free transport systems was developed by Puritan. This kind of foam swab made from polyurethane foam was embraced by the point-of-care community. As the first specimen collection device used for its collect and release attributes by the rapid POC diagnostic companies, it is still widely used today. And in a word, this was truly the first elution swab on the market.
2000s: Flocked Swabs
device, trademarked HydraFlock, is widely used in the clinical diagnostic field for improved sample collection, complete sample release and patient comfort. The unique micro-geometry of each HydraFlock fiber increases the surface area on the swab tip. This fiber geometry, best described as ‘split ends’ provides increased surface tension and micro channels for the collection and release of small single cells.