title: [Determination of bloodstain formation time by RNA analysis].
abstract: OBJECTIVE
  To investigate the expression of 18S rRNA and beta-actin mRNA in bloodstain between 8 and 15 days after death and extrapolate the time of bloodstain formation.
  
  
  METHODS
  RNA in dried bloodstain at different times was extracted, then quantified for 18S rRNA and beta-actin mRNA by real-time RT-PCR. The bloodstain formation time was deduced based on the changes of the ratio of 18S rRNA to beta-actin mRNA at different time points.
  
  
  RESULTS
  The ratio of 18S rRNA to beta-actin mRNA increased gradually with time, indicating that rRNA and mRNA degraded in different rate with time. CONCLUSION; The ratio of 18S rRNA to beta-actin mRNA could be used for estimating the time of bloodstain formation in some period.
authors.affiliation: Shanghai Key Laboratory of Crime Science Evidence, Key Laboratory of Forensic Evidence and Science Technology, Ministry of Public Security, Institute of Forensic Science, Shanghai Public Security Bureau, Shanghai 200083, China. xxnnxy@hotmail.com
authors.forename: Yan
authors.initials: Y
authors.lastname: Xu
authors.forename: Wei
authors.initials: W
authors.lastname: Jiang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Ping
authors.forename: Gang
authors.initials: G
authors.lastname: Bi
authors.forename: Lian-Kang
authors.initials: LK
authors.lastname: Chen
authors.forename: Huai-Gu
authors.initials: HG
authors.lastname: Zhou
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism*; D001801:Blood Stains; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D005554:Forensic Medicine / Q000379:methods; D006801:Humans; D011180:Postmortem Changes; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D012337:RNA, Ribosomal, 18S / Q000235:genetics / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D013997:Time Factors
chemical_list: D000199:Actins; D018076:DNA, Complementary; D012333:RNA, Messenger; D012337:RNA, Ribosomal, 18S