search
for
 About Bioline  All Journals  Testimonials  Membership  News  Donations


Memórias do Instituto Oswaldo Cruz
Fundação Oswaldo Cruz, Fiocruz
ISSN: 1678-8060
EISSN: 1678-8060
Vol. 107, No. 8, 2012, pp. 965-968
Bioline Code: oc12160
Full paper language: English
Document type: Research Article
Document available free of charge

Memórias do Instituto Oswaldo Cruz, Vol. 107, No. 8, 2012, pp. 965-968

 en Stool sample storage conditions for the preservation of Giardia intestinalis check for this species in other resources DNA
Kuk, Salih; Yazar, Suleyman & Cetinkaya, Ulfet

Abstract

Stool is chemically complex and the extraction of DNA from stool samples is extremely difficult. Haemoglobin breakdown products, such as bilirubin, bile acids and mineral ions, that are present in the stool samples, can inhibit DNA amplification and cause molecular assays to produce false-negative results. Therefore, stool storage conditions are highly important for the diagnosis of intestinal parasites and other microorganisms through molecular approaches. In the current study, stool samples that were positive for Giardia intestinalis check for this species in other resources were collected from five different patients. Each sample was stored using one out of six different storage conditions [room temperature (RT), +4°C, -20°C, 70% alcohol, 10% formaldehyde or 2.5% potassium dichromate] for DNA extraction procedures at one, two, three and four weeks. A modified QIAamp Stool Mini Kit procedure was used to isolate the DNA from stored samples. After DNA isolation, polymerase chain reaction (PCR) amplification was performed using primers that target the ß-giardin gene. A G. intestinalis-specific 384 bp band was obtained from all of the cyst-containing stool samples that were stored at RT, +4°C and -20°C and in 70% alcohol and 2.5% potassium dichromate; however, this band was not produced by samples that had been stored in 10% formaldehyde. Moreover, for the stool samples containing trophozoites, the same G. intestinalis-specific band was only obtained from the samples that were stored in 2.5% potassium dichromate for up to one month. As a result, it appears evident that the most suitable storage condition for stool samples to permit the isolation of G. intestinalis DNA is in 2.5% potassium dichromate; under these conditions, stool samples may be stored for one month.

Keywords
Giardia intestinalis - DNA isolation - storage conditions - stool

 
© Copyright 2012 - Memorias do Instituto Oswaldo Cruz
Alternative site location: http://memorias.ioc.fiocruz.br

Home Faq Resources Email Bioline
© Bioline International, 1989 - 2017, Site last up-dated on 05-Dec-2017.
Site created and maintained by the Reference Center on Environmental Information, CRIA, Brazil
System hosted by the Internet Data Center of Rede Nacional de Ensino e Pesquisa, RNP, Brazil