Hallo,

you may be aware, but I wrote a review about this topic some years ago (still fully valid) - here is a link form the journal, but also found at my ResearchGate site).

https://www.wtm.at/explorer/WTM/Archiv/2013/WTM_09-10-2013_Artikel_3_Palme.pdf

Palme, R., Touma, C., Arias, N., Dominchin, MF., Lepschy, M. (2013): Steroid extraction: Get the best out of faecal samples. Wiener Tierärztl. Mschrift – Vet. Med. Austria 100, 238-246.

As always,

Thank you so very much Prof.

Your articles have always been so helpful.

I will read the article again.

Regards Prof.

Hi Peter

Fresh feces contain surely contain higher level of water so if the hydration of your samples is different you can have some problem when you have to analyse their fecal hormonal levels

regards

Carlo

If you have a lot of samples, not so much difference in water content between fecal samples (depending on the species) and a good paralelism comparing dry and wet fecal samples (a good and significant correlation) you can analyse wet samples. Anyway, dry samples are the gold standard.

Carlo Cinque

thank you so much for those points

Nei Moreira

thank you too...

Dear Dr Peter,

You will need to consider several points to decide which method of extraction is most suitable for your lab.

1. Drying removes water content so you will not have any influence of water from the sample itself on the extraction efficiency.

2. Drying eliminates micro-organisms and possible pathogens within the feces so it may also be a requirement of your biosafety protocols.

3. If you do not have appropriate equipment to dehydrate the samples such as lyophilizer (conventional oven may affect results) then it could be a problem.

4. If you are going to start up for any new species then it is best to stick with one of the method as you cannot compare the results of previous studies if they used the other method.

Good luck with setting up.

Regards,

Edward

thank you so very much Edward J Narayan

all points listed above are duly noted Dr.

once again, many thanks