Quality and quantity of DNA isolated from frozen urine in population-based research.
In several population-based studies in the past urine samples were collected and stored for future research. We set out to determine the reliability of using such samples for genotyping DNA markers in epidemiologic research. A source of DNA extracted from exfoliated nucleated cells in urine is provided by the DOM cohort, in which specimens were collected 15-25 years ago. We have examined the quality of the DNA in 48 of these samples by measuring the amount of DNA isolated and its ability to provide an adequate PCR template for amplicons of different lengths. MTHFR polymorphism was analyzed in 644 specimens to determine the inter- and intraobserver reproducibility. Although the DNA amount was variable, 26 to 89% of the samples, depending both on the length of the PCR amplicon and on PCR conditions, yielded a visible PCR product. The intra- and interobserver agreements were comparable (kappa 0.86 and 0.88, respectively). Our results demonstrate that frozen urine samples can be used for DNA typing studies in women after prolonged periods of storage, but with sometimes unpredictable results. Ultimately, the genotype success rate was 89.3%. Urine collection can be considered as a useful method of obtaining DNA in large cohort studies and other circumstances when blood samples cannot be obtained or have not been stored.
van der Hel
Olga L
OL
Julius Center for General Practice and Patient Oriented Research, University Medical Center, 3508 GA Utrecht, The Netherlands. o.vanderhel@jc.azu.nl
van der Luijt
Rob B
RB
Bueno de Mesquita
H B
HB
van Noord
Paul A H
PA
Slothouber
Barbara
B
Roest
Mark
M
van der Schouw
Yvonne T
YT
Grobbee
Diederick E
DE
Pearson
Peter L
PL
Peeters
Petra H M
PH
D004247:DNA / Q000737:chemistry / Q000235:genetics / Q000652:urine*; D017931:DNA Primers; D004812:Epidemiologic Methods; D005260:Female; D005374:Filtration; D005615:Freezing; D005838:Genotype; D006801:Humans; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D009426:Netherlands; D015588:Observer Variation; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000379:methods*; D011110:Polymorphism, Genetic; D013048:Specimen Handling
D017931:DNA Primers; D004247:DNA; D000587:Oxidoreductases Acting on CH-NH Group Donors; D042965:Methylenetetrahydrofolate Reductase (NADPH2)