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Hennessy

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question/ storing MLSS sample for microscopic eval
Jan 08^th, 2010, 11:50am

Per the 3rd edition manual on causes/control of activated sludge bulking, foaming, and..... it says to get 100 mL in a plastic screw cap bottle less than 1/2 way filled. The sample should be stored at 4 degree C- Low MCRT no more than 3-4 days, high MCRT no more than 7-10 days. My question is regarding preservation on the car rides (one of the samples I'm going to be looking at is a 4 hours total of driving/ another one only an hour.) I know I should avoid ice to prevent floc break-up. Would something like a lunch box be okay to put the sample in during the ride?

thanks in advance,
cheers

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Victor

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Re: question/ storing MLSS sample for microscopic eval
Reply #1 - Jan 8^th, 2010, 5:20pm

Ryan:

If the organisms are accustomed to having very little food around (long MCRT's) then a long sample detention time is not going to have detrimental effects (thus the 7-10 day rule). As a matter of fact, I've had samples shipped 2nd day at room temperature and they look great! I think that the working parameter here is that they should not get warm or hot because this increases the possibility of septicity (that is why they ask that the sample bottle be half empty!) and lead to erroneous assumptions. 4 hours should be fine, keep out of warm sun though.

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Hennessy Ex Member	Re: question/ storing MLSS sample for microscopic eval Reply #2 - Jan 9^th, 2010, 8:58am thanks Victor- warm sun shouldn't be a problem here, today the windchill is -10
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DS

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Re: question/ storing MLSS sample for microscopic eval
Reply #3 - Jan 9^th, 2010, 10:35am

I agree with Victor.
You do not need to cool the samples, room temperature (about 20°C)is OK. Ice packs can be detrimental (partial freezing of the sample). At least the same volume of headspace (as the liquid volume) is required to avoid septicity. 10 mL of sample is in most cases more then enough. Unbreakable and water tight sample containers should be used.

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Hennessy Ex Member	Re: question/ storing MLSS sample for microscopic eval Reply #4 - Jan 9^th, 2010, 12:57pm thanks, just to make sure I'm clear with this the sample should still be refrigerated for storage (overnight for one, three days for the other) right? but room temperature for the car ride will be okay.
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Victor YaBB Moderator Offline Escherichia coli Happens! Posts: 1269 Company or Organization: www.santacruzproductions.com	Re: question/ storing MLSS sample for microscopic eval Reply #5 - Jan 9^th, 2010, 1:00pm that's right.
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