title: Typeability of DNA in Touch Traces Deposited on Paper and Optical Data Discs.
abstract: BACKGROUND
  Nucleated epithelial cells that are transferred by casual touching and handling of objects are the primary source of biological evidence that is found in high-volume crimes. Cellular material associated with touch traces usually contains low levels of DNA template making it challenging to acquire an informative profile.
  
  
  OBJECTIVE
  The main purpose of this study was to examine the efficacy of DNA typing in fingerprints deposited on optical data discs and the office paper.
  
  
  METHODS
  Latent fingerprints were made by 60 subjects of both sexes (30 males and 30 females). A highly effective DNA extraction method with QIAamp DNA Mini Kit (Qiagen) and an increased sensitivity PCR by AmpFlSTR® NGM™ Amplification Kit (Applied Biosystems) carried out at standard 30 cycles and at increased 34 cycles were used.
  
  
  RESULTS
  The mean value of total DNA recovery was 0.4 ng from CDs/DVDs and 0.3 ng from the office paper. Amplification of Low Template DNA (LT-DNA) resulted in improved analytical success by increasing the number of PCR cycles from standard 30 to 34. On the other hand, the increased PCR cycles resulted in allele drop-ins showing additional peaks, the majority of which were outside the stutter positions.
  
  
  CONCLUSIONS
  Rigorous procedures and interpretation guidelines are required during LT-DNA for producing reliable and reproducible DNA profiles for forensic purposes.
authors.affiliation: Department of Criminalistics and Forensic Medicine, University of Warmia and Mazury in Olsztyn, Poland.
authors.forename: Ireneusz
authors.initials: I
authors.lastname: Sołtyszewski
authors.affiliation: Department of Forensic Medicine, Medical University of Bialystok, Poland.
authors.forename: Michał
authors.initials: M
authors.lastname: Szeremeta
authors.affiliation: Department of Forensic Medicine, Medical University of Bialystok, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Skawrońska
authors.affiliation: Department of Forensic Medicine, Medical University of Bialystok, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Niemcunowicz-Janica
authors.affiliation: Department of Forensic Medicine, Medical University of Bialystok, Poland.
authors.forename: Witold
authors.initials: W
authors.lastname: Pepiński
mesh_terms: D016250:Compact Disks; D004247:DNA / Q000302:isolation & purification*; D016172:DNA Fingerprinting / Q000295:instrumentation / Q000379:methods*; D004847:Epithelial Cells / Q000737:chemistry*; D005260:Female; D006801:Humans; D008297:Male; D010209:Paper; D016133:Polymerase Chain Reaction / Q000295:instrumentation; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results
chemical_list: D011933:Reagent Kits, Diagnostic; D004247:DNA