Screening Test for Shed Skin Cells by Measuring the Ratio of Human DNA to Staphylococcus epidermidis DNA.
A novel screening method for shed skin cells by detecting Staphylococcus epidermidis (S. epidermidis), which is a resident bacterium on skin, was developed. Staphylococcus epidermidis was detected using real-time PCR. Staphylococcus epidermidis was detected in all 20 human skin surface samples. Although not present in blood and urine samples, S. epidermidis was detected in 6 of 20 saliva samples, and 5 of 18 semen samples. The ratio of human DNA to S. epidermidisDNA was significantly smaller in human skin surface samples than in saliva and semen samples in which S. epidermidis was detected. Therefore, although skin cells could not be identified by detecting only S. epidermidis, they could be distinguished by measuring the S. epidermidis to human DNA ratio. This method could be applied to casework touch samples, which suggests that it is useful for screening whether skin cells and human DNA are present on potential evidentiary touch samples.
Department of Forensic Medicine, Juntendo University School of Medicine, 2-1-1, Hongo, Bunkyo-Ku, Tokyo, 113-8421, Japan.
Hiroaki
H
Nakanishi
National Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, Chiba, 277-0882, Japan.
Takeshi
T
Ohmori
Department of Forensic Medicine, Saitama Medical University, 38 Morohongo, Moroyama, Saitama, 350-0495, Japan.
Masaaki
M
Hara
Department of Forensic Medicine, Saitama Medical University, 38 Morohongo, Moroyama, Saitama, 350-0495, Japan.
Shirushi
S
Takahashi
Department of Legal Medicine, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi, 321-0293, Japan.
Akira
A
Kurosu
Department of Forensic Medicine, Saitama Medical University, 38 Morohongo, Moroyama, Saitama, 350-0495, Japan.
Aya
A
Takada
Department of Forensic Medicine, Juntendo University School of Medicine, 2-1-1, Hongo, Bunkyo-Ku, Tokyo, 113-8421, Japan.
Kazuyuki
K
Saito
D001826:Body Fluids / Q000737:chemistry; D004247:DNA; D004269:DNA, Bacterial / Q000032:analysis*; D044707:Forensic Sciences; D006801:Humans; D060888:Real-Time Polymerase Chain Reaction; D012867:Skin / Q000166:cytology*; D013212:Staphylococcus epidermidis / Q000235:genetics*
D004269:DNA, Bacterial; D004247:DNA
Staphylococcus epidermidis; forensic science; human DNA; real-time polymerase chain reaction; screening test; touch DNA