Do I need to re-test if the yeast colony count in my air plate testing is reported as <1cfu/plate?
Do I need to re-test if the yeast colony count in my air plate testing is reported as <1cfu/plate ?
Do I need to re-test if the yeast colony count in my air plate testing is reported as <1cfu/plate ?
So, is this a MPN procedural result ?
Or simply means no visible colonies on a plate ?
It also possibly depends on the context, eg why you are doing it ? how you are doing it ? do you have reason to disbelieve the result ?
it is usually analytically recommended to perform at least one duplicate test for statistical/consistency reasons..
So, is this a MPN procedural result ?
Or simply means no visible colonies on a plate ?
It also possibly depends on the context, eg why you are doing it ? how you are doing it ? do you have reason to disbelieve the result ?
it is usually analytically recommended to perform at least one duplicate test for statistical/consistency reasons..
Its for enviornmental air testing, we dont have any ready to eat product. Its a bakery and we just test the non-food contact surface and air/water used in the facility. I have sent 6 plates to lab and most of them came like <1cfu. Usually we get 0 yeast colonies but this <1 makes me feel like the test was not validated. I mean would the auditor accept it or its better to test one more time to be on the safe side
What's your Y&M limit for the air? We've established <100 cfu, and usually it comes back as 1-50 cfu. Is your limit 0? It's hardly possible unless your facility is as sterile as an operating room:)
Its for enviornmental air testing, we dont have any ready to eat product. Its a bakery and we just test the non-food contact surface and air/water used in the facility. I have sent 6 plates to lab and most of them came like <1cfu. Usually we get 0 yeast colonies but this <1 makes me feel like the test was not validated. I mean would the auditor accept it or its better to test one more time to be on the safe side
I'd suggest a discussion with your lab is probably the best place to start.
The difference between 0cfu and <1cfu is probably largely semantic/philosophical - for plate count methods it's not unusual to report a finding of no colonies as <1cfu (or <10, <1000 etc dependent on dilution rate) rather than as 0cfu.
From the auditor perspective, they should hopefully be sufficiently familiar with micro to understand that <1 still means that no counts were found, i.e. it's not really a "worse" result than 0cfu. If you're still using the same lab as for previous results, it may well just be the case that they've changed how they report results for plates where no colonies were observed.
FWIW the standard result for many of the products I've worked with over many years is that no counts have been found for yeasts, but I honestly can't remember the last time I saw a lab report that said 0cfu/g rather than <x cfu/g.
Do I need to re-test if the yeast colony count in my air plate testing is reported as <1cfu/plate ?
This is a sedimentation (settle) plate , Yes ?
You could consult a micro handbook, eg BAM, as to the appropriate way of expressing a finding a null detection for Y(&M?). That's your validity.
Then, if lab format is different to text iin BAM, and you care, could ask the lab how they justify their presentation methodology.
PS - The auditor might just ask if the Plate(s) was left on a desk for 1 minute in the morning before work started?