Prepare media and test the Sunfield batch release samples

What is going on

Sunfield Foods has four retail packs of chilled dip in for Listeria, Salmonella and standard plate count under job CJ-26-0418 with a 48 hour turnaround for product release. Biosafety cabinet one is tagged out after airflow alarms, so all work is in cabinet two. Last month a Listeria positive control failed on an overheated media batch, and every media batch is now quality checked with controls before use. The autoclave is approaching its calibration due date and Hamish McLeod wants the cycle chart and biological indicator result recorded. Incubator temperatures must be logged throughout the run because a door seal recently failed on another unit.

Your brief

Prepare and quality check the media, set up the samples and controls using aseptic technique in the certified cabinet, incubate and read the tests on time, record all results and equipment checks, and submit the batch for review within the client's turnaround.

Work through it

You do not need to do it all. Doing a few of these will show you what the work is like. Your ticks and notes stay on this device.

• Read the media preparation method and the chemical and biological risk assessment for the pathogen tests, and confirm cabinet two and the incubators show In service in the equipment register.
• Prepare the media batch, record weights, volumes, pH and the autoclave cycle chart, and attach the biological indicator result to the media batch record.
• Inoculate the positive and negative controls on the new media batch and record the media batch as quarantined until the controls are read.
• Weigh and homogenise the four samples in cabinet two using aseptic technique that prevents cross-contamination, and set up the enrichment and plate count series.
• Log the incubator temperatures at the start, during and end of the run from the calibrated thermometers, and note any excursion in the nonconformance register.
• Read and record the plates and enrichment results at the method times, confirm any presumptive positives as the method requires, and decontaminate all cultures by autoclaving.
• Update the sample register to Awaiting review with results and control outcomes, and hand the worksheet to Hamish McLeod for technical review.

What someone in this role would produce

• Media batch record with control results
• Aseptic set-up worksheet for the four samples
• Incubator temperature log for the run
• Results worksheet with control outcomes
• Sample register status updates