title: Evaluation of 5-methyl-2'-deoxycytidine stability in hydrolyzed and nonhydrolyzed DNA by HPLC-UV.
abstract: BACKGROUND
  Although the determination of 5-methyl-2'-deoxycytidine (5-MedC) in various biological samples is gaining increasing scientific interest, there are no data available regarding its stability.
  
  
  RESULTS
  We have currently evaluated the stability of 5-MedC and 2'-deoxycytidine (dC) at -20°C, both in hydrolyzed and nonhydrolyzed calf thymus DNA (CT DNA), as well as following repetitive freeze-thaw cycles. HPLC-UV was used for the accurate determination of the two 2'-deoxynucleosides. Statistical evaluation of the results revealed that 5-MedC and dC were stable in hydrolyzed CT DNA for at least 7 days and in nonhydrolyzed CT DNA for at least 65 days, when these were stored at -20°C. Furthermore, both 2'-deoxynucleosides were stable for at least three repetitive freeze-thaw cycles.
  
  
  CONCLUSIONS
  By using HPLC-UV, we have evaluated the stability of 5-MedC and dC under storage conditions and repetitive freeze-thaw cycles. Our results are informative about the way samples should be handled and stored in epigenetic studies.
authors.affiliation: Laboratory of Forensic Medicine & Toxicology, School of Medicine, Aristotle University of Thessaloniki, Greece. kovatsi@med.auth.gr
authors.forename: Leda
authors.initials: L
authors.lastname: Kovatsi
authors.forename: Domniki
authors.initials: D
authors.lastname: Fragou
authors.forename: Victoria
authors.initials: V
authors.lastname: Samanidou
authors.forename: Samuel
authors.initials: S
authors.lastname: Njau
authors.forename: Sofia
authors.initials: S
authors.lastname: Kouidou
authors.forename: Alexis
authors.initials: A
authors.lastname: Bailey
mesh_terms: D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004247:DNA / Q000737:chemistry*; D019175:DNA Methylation; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000032:analysis*; D057890:Epigenomics; D005615:Freezing; D006801:Humans; D006868:Hydrolysis; D012044:Regression Analysis; D012996:Solutions; D013048:Specimen Handling; D013056:Spectrophotometry, Ultraviolet
chemical_list: D012996:Solutions; D003841:Deoxycytidine; D004247:DNA; C427203:calf thymus DNA; C016569:5-methyldeoxycytidine