Sigma-Swabs® Great stains - no haze!

Since the earliest days of microbiology, gram staining has been the starting point for many bacteriological investigations. Whether at the doctor's office for an initial presumptive characterisation based on stain and morphology, or at the laboratory bench as the starting point for a complete description of the prevalent organism.

This has carried on into the era of transport swabs, and even charcoal medium offers little interference with Gram stains. It has been reported, however, that some newer liquid swab based transport swabs with nylon flocked swab applicators release substances into the stain that cause interference with the staining process.

A study has been presented at this month's ASM General Meeting in San Diego¹ that shows while Sigma-Swabs® (Dry swabs) and Sigma-Transwabs® (with liquid Amies medium) give clear Gram stains with no interfering background, both the E-swab transport swab (with liquid Amies medium), and its component dry flocked swab have a hazy background.

Further testing with acridine orange stain showed interference suggestive of possible proteinaceous additives.

Sigma-Swabs® and Sigma-Transwabs® have a swab bud made from open celled polyurethane foam (Macrofoam™) with no additives and no non-viables for top quality stains without interference.

For great Gram stains without haze - choose Sigma-Swabs® and Sigma-Transwabs®

Reference:
1. Stuczen, M., & Edwards-Jones, V., 2010, Comparison of the quality of Gram stain prepared using different swab transport systems, 110th General Meeting of American Society of Microbiology, San Diego.