The 2000-2001 GEP-ISFG Collaborative Exercise on mtDNA: assessing the cause of unsuccessful mtDNA PCR amplification of hair shaft samples.
We report the results of Spanish and Portuguese working group (GEP) of International Society of Forensic Genetics (ISFG) Collaborative Exercise 2001-2002 on mitochondrial DNA (mtDNA) analysis. 64 laboratories from Spain, Portugal and several Latin-American countries participated in this quality control exercise. Five samples were sent to the participating laboratories, four blood stains (M1-M4) and a sample (M5) consisting of two hair shaft fragments. M4 was non-human (Felis catus) in origin; therefore, the capacity of the labs to identify the biological source of this sample was an integral part of the exercise. Some labs detected the non-human origin of M4 by carrying out immuno-diffussion techniques using antihuman serum, whereas others identified the specific animal origin by testing the sample against a set of animal antibodies or by means of the analysis of mtDNA regions (Cyt-b, 12S, and 16S genes). The results of the other three human blood stains (M1-M3) improved in relation to the last Collaborative Exercises but those related to hairs yielded a low rate of success which clearly contrasts with previous results. As a consequence of this, some labs performed additional analysis showing that the origin of this low efficiency was not the presence of inhibitors, but the low quantity of DNA present in these specific hair samples and the degradation. As a general conclusion the results emphasize the need of external proficiency testing as part of the accreditation procedure for the labs performing mtDNA analysis in forensic casework.
Prieto
Lourdes
L
Comisara General de Policía Científica, Sección de Biología-ADN, Madrid, Spain. biologia.adn@policia.es
Montesino
Marta
M
Salas
Antonio
A
Alonso
Antonio
A
Albarrán
Cristina
C
Alvarez
Sara
S
Crespillo
Manuel
M
Di Lonardo
Ana Maria
AM
Doutremepuich
Christian
C
Fernández-Fernández
Isabel
I
de la Vega
Alberto González
AG
Gusmão
Leonor
L
López
Carlos M
CM
López-Soto
Manolo
M
Lorente
José A
JA
Malaghini
Marcelo
M
Martínez
Carlos A
CA
Modesti
Nidia M
NM
Palacio
Ana Maria
AM
Paredes
Manuel
M
Pena
Sergio D J
SD
Pérez-Lezaun
Anna
A
Pestano
José J
JJ
Puente
Jorge
J
Sala
Andrea
A
Vide
MariaConceiçao
M
Whittle
Martín R
MR
Yunis
Juan J
JJ
Gómez
Josefina
J
D000068:Accreditation; D000818:Animals; D001801:Blood Stains; D002415:Cats; D019411:Clinical Laboratory Techniques / Q000592:standards*; D004272:DNA, Mitochondrial / Q000032:analysis*; D005554:Forensic Medicine / Q000592:standards*; D006197:Hair; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods / Q000592:standards*; D011174:Portugal; D011786:Quality Control; D012955:Societies, Medical; D013030:Spain
D004272:DNA, Mitochondrial