Quality control in diagnostic molecular pathology in the Netherlands; proficiency testing for patient identification in tissue samples.
OBJECTIVE
To describe the evolution of proficiency testing for molecular diagnostic pathology with respect to determining unambiguously the patient identity of tissue samples by microsatellite analysis.


METHODS
Four rounds of quality control exchanges of samples from different patients were sent with the purpose of identifying the correct origin of these samples. The samples were either paraffin wax embedded sections on glass, sections in tubes, or isolated DNA. Blinded samples were distributed to all participating laboratories. No restrictions to the method and short tandem repeat markers used for identification were imposed.


RESULTS
In four subsequent rounds the number of participating laboratories increased from three to 10. The numbers of samples tested increased in time from five to 12. The microsatellite markers used by the different laboratories showed little overlap. In the first three rounds, in which isolated DNA was provided, all samples were accurately classified irrespective of the microsatellite markers used. In the last round, which also included paraffin wax embedded sections, a small number of laboratories experienced problems, either with amplification or incorrect classification of a few samples.


CONCLUSIONS
Proficiency testing was useful, and showed country wide high quality and correct identification of (patient) samples with molecular techniques for diagnostic purposes.
Thunnissen
F B J M
FB
Department of Pathology, Canisius Wilhelmina Hospital, 6532 SZ Nijmegen, The Netherlands. e.thunnissen@cwz.nl
Tilanus
M G J
MG
Ligtenberg
M J L
MJ
Nederlof
P M
PM
Dinjens
W N M
WN
Meulemans
E
E
Van den Brule
A J C
AJ
van Noesel
C J M
CJ
de Leeuw
W J F
WJ
Schuuring
E
E
D004247:DNA / Q000032:analysis; D005819:Genetic Markers; D005821:Genetic Techniques / Q000592:standards*; D006801:Humans; D007753:Laboratories / Q000592:standards; D018895:Microsatellite Repeats; D009426:Netherlands; D016612:Paraffin Embedding; D010338:Pathology, Clinical / Q000592:standards*; D011786:Quality Control; D020080:Tandem Repeat Sequences
D005819:Genetic Markers; D004247:DNA