Dear Ahmad,

You can use different methods for DNA Extraction. In my experience, AccuPrep Stool DNA Extraction Kit (Bioneer) is a good and easy to use DNA extraction kit. In addition, samples freeze and thaw before extraction process, can increased yield of DNA.  

Dear Ahmad Amro,

I think the Researcher Vitor Luz (https://www.researchgate.net/profile/Vitor_Carvalho11) could help you concerning to this question.

Kind regards.

Dear Ahmad

One of the best and useful article in this topic is: Giardia intestinalis: DNA extraction approaches to improve PCR results.

In this article the authors compare some methods and available at : Experimental Parasitology 128 (2011) 159–162

You also can extract DNA directly from infected stool using QIAamp DNA minikit with some pre treatment.

Dear Ahmad, I got good results using Blood and Tissue Kit from Qiagen.

My very best regards,

Dear Ahmad

We use the Qiagen stool kit with great success. I have published this: 

Elwin K, Fairclough HV, Hadfield SJ, Chalmers RM. Giardia duodenalis typing from stools: a comparison of three approaches to extracting DNA, and validation of a probe-based real-time PCR typing assay. Journal of Medical Microbiology, 2014; 63: 38-44

and recently this good paper was published:

J Microbiol Methods. 2016 May 27. pii: S0167-7012(16)30107-5. doi:

10.1016/j.mimet.2016.05.020. [Epub ahead of print]

Evaluation of five commercial methods for the extraction and purification of DNA

from human faecal samples for downstream molecular detection of the enteric

protozoan parasites Cryptosporidium spp., Giardia duodenalis, and Entamoeba spp.

Paulos S(1), Mateo M(2), de Lucio A(3), Mingo MH(3), Bailo B(3), Saugar JM(3),

Cardona GA(4), Fuentes I(3), Mateo M(5), Carmena D(6).

Good Luck.

Dear Ahmad

For extraction of DNA from fecal specimens, it would be better to use kits specific for extraction of DNA fro feces such as QIAamp DNA minikit (Qiagen, Germany). Because feces contain so many inhibitors which may interfere with PCR yield.