6 replies to this topic

[ahmed alabboud]

good day dears:

I  want to know how we can test the quality of indoor air by microbiology test . as i know we can use method test of exposed Agar petri dishes but  i want to help me for more information about that test method and what the References.

thank you

[BrummyJim]

From my experience processing these in a major micro lab in the UK, they are processed in the same way as any poured/streaked plates or the same agar. The plates should be exposed for 30 minutes for sampling and are then incubated at the required time/temperature (e.g. 72 hours@25⁰ for Rose Bengal yeasts & moulds, 48 hours @37⁰ for Plate Count Agar TVC)

[ahmed alabboud]

THANK YOU MR BrummyJim

[ahmed alabboud]

good day dears :

I ask if we exposed petri dish for 30 minutes and the result was 15 colonies  how we can calculate  cfu/m3  kindly mention to references .

 

thanks

Edited by Charles.C, 03 February 2017 - 07:21 AM.
combined, see post 7

[Charles.C]

good day dears :

I ask if we exposed petri dish for 30 minutes and the result was 15 colonies  how we can calculate  cfu/m3  kindly mention to references .

 

thanks

 

Hi ahmed,

 

Afaik, settle plate data is currently more often used to calculate cfu/area/time.

Impaction techniques are commonly used  if cfu/m3 values are required.

 

Nonetheless, a value for cfu/cm3 for yr settle plate data can be estimated via Omeliansky's formula as shown in this post 18 –

 

 http://www.ifsqn.com...ria/#entry95042

(also see Post6/method2, Post17)

 

A reference illustrating use of the Omeliansky formula  is attached.

 Sedimentation with the Omeliansky formula,2012.pdf   44.61KB   58 downloads

Edited by Charles.C, 03 February 2017 - 07:21 AM.
combined, see post 7

[ahmed alabboud]

thanks dear Charles.. best regards

Edited by Charles.C, 03 February 2017 - 07:21 AM.
combined, see post 7

[CMHeywood]

Also see this recent post: 

Indoor air test by exposed petri dishes

Started by ahmed alabboud, Jan 29 2017 05:11 AM

 

Sorry, I don't know how to give you a link to this post, but was in the recent email from IFSQN.

Edited by Charles.C, 03 February 2017 - 07:18 AM.
thanks, I have now combined the 2 threads