title: A comparative study of three extraction protocols of DNA from nails: Potential use in the diagnosis of onychomycoses.
abstract: Molecular techniques can be useful adjuncts to the diagnosis of onychomycoses. However, the nail presents difficulties in the extraction of its DNA. The comparison of three extraction protocols of DNA from nails and their ranking for possible use in the molecular diagnosis of onychomycoses are described. Extraction was performed on weighed nail clippings of equal size from positive (31) or negative (14) samples, according to the culture result. At Prot1, the extraction was performed according to Tahir and Watson, with an additional step implementing silica columns. At Prot2, the methodology proposed by the Statens Serum Institute of Copenhagen was used. At Prot3, DNA was extracted by the use of magnetic separation after homogenisation with glass beading. The evaluation parameters were DNA purity, DNA concentration, total DNA yield/g of tissue, cost and duration. The multiples of the means of medians of the first three parameters, for each protocol, were calculated. Prot3 showed the highest DNA purity. Prot2 presented the highest DNA concentration and DNA yield/g of tissue, while it was the cheapest and shortest. In total, the three protocols were graded as Prot2>Prot1>Prot3. The second method, although had a lower DNA purity, presented the higher DNA concentration and DNA yield, while its duration and cost were also favourable.
authors.affiliation: 1st Department of Microbiology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: T
authors.initials: T
authors.lastname: Kotrotsiou
authors.affiliation: 1st Department of Microbiology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: A
authors.initials: A
authors.lastname: Chatzimichaloglou
authors.affiliation: 2nd Department of Dermatology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: A
authors.initials: A
authors.lastname: Nasr
authors.affiliation: Department of Experimental Physiology, Medical School, Aristotle University of Thessaloniki, Greece.
authors.forename: E
authors.initials: E
authors.lastname: Spandou
authors.affiliation: 2nd Department of Dermatology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: A
authors.initials: A
authors.lastname: Patsatsi
authors.affiliation: 2nd Department of Dermatology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: D
authors.initials: D
authors.lastname: Sotiriadis
authors.affiliation: 1st Department of Microbiology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: T-A
authors.initials: TA
authors.lastname: Vyzantiadis
mesh_terms: D053000:Analytic Sample Preparation Methods; D004247:DNA / Q000302:isolation & purification*; D004271:DNA, Fungal / Q000302:isolation & purification*; D006801:Humans; D009262:Nails / Q000737:chemistry / Q000382:microbiology; D014009:Onychomycosis / Q000175:diagnosis*; D016133:Polymerase Chain Reaction
chemical_list: D004271:DNA, Fungal; D004247:DNA
keywords: extraction methods; nail DNA; onychomycoses