Staphylococcus aureus - WS

This proficiency testing sample is produced in accordance with ISO/IEC 17043:2010. All information regarding the use of this material can be found in the reporting packet supplied for each sample.

This PT sample is designed for the quantitative analysis of S. aureus. The PT sample is provided in duplicate as a stable dehydrated Vitroid requiring hydration. The additional sample is provided for mishaps in the lab. A 100 mL of sterile hydration fluid is supplied with the PT sample. This is a phosphate buffer. The dehydrated Vitroid sample is stable for a time exceeding the study schedule.

Sample preparation
Allow the capped sample vial and hydrating fluid to equilibrate to room temperature.
The hydration fluid is sterile and may be stored at room temperature up to the expiration date listed on the bottom, refrigeration is not necessary for the hydration fluid.
Open the sample vial and aseptically transfer the Vitroid to the hydrating fluid.
NOTE: The Vitroid is the colored disk on top of the cotton. The opaque beads below the cotton keep container dry and are not biologicals.
Allow the Vitroid to dissolve completely this may take up to 15 minutes.
Mix by inverting gently several times, shaking may cause the cap to leak. This represents the sample for analysis. Incubate at the temperature required by your method.
Temperature requirements are rigorous, higher temperatures will kill the organisms and lower temperatures may suppress growth.
Minimum incubation time is 24 hours. Further may be necessary depending on the method and media.
Further dilutions are recommended to achieve a proper count, but base all counts on the whole volume sample.

Proficiency testing samples are presented as single blind. No values for the samples are released until the testing period concludes. Values of analytes vary lot to lot.