Information on the Ring Trial Prenatal rapid test


There are two different methods to check prenatal samples (e.g. amniotic fluid) without cell culture for the most relevant trisomies 13, 18 and 21 and for gonosomal aneuploidies. This ring trial checks the technical performance of the interphase-FISH or QF-PCR technique, the evaluation of the data, the reporting and the interpretation of the results in order to simulate a real diagnostic setting. In a second case the formal knowledge is proved (e.g. ISCN nomenclature, interpretation).

Performance interval

Once per year.


A methanol-acetic acid fixed cell suspension and/or extracted DNA is sent out together with clinical information of a fictitious pregnant woman. At the application for the ring trial the participants have to decide for which of the two methods they want to take part (they can choose both methods, too).
Under normal transport conditions by courier service, aliquoted samples are stable for up to 5 days. Usually the samples are delivered within one or two days.


The interphase FISH or the QF-PCR test should be carried out according to the own laboratory SOP. A diagnostic report has to be written and uploaded which includes the result of the analysis and the interpretation in relation to the diagnostic question. It is possible to upload the lab protocols, too.
The 2nd case is provided with a theoretical task (e.g. ISCN nomenclature).


Correct result; interpretation in relation to the clinical indication.
Also: Interpretation of the result in relation to the diagnostic question, recommendation of Genetic counseling, limits of the technique, time to report, ISCN formula; hybridization efficiency.


A certificate (valid for two years) will be provided that states whether or not the participation was successful (depending on the correctness of the result).

Ring trial management

M Sc Sarah Matos Meder
MVZ Institut für Klinische Genetik und Tumorgenetik Bonn GmbH
Maximilianstr. 28d
53111 Bonn
Tel. 0228 969686724

Dr. rer. med. Marion Krüger
MCL Med. Laboratorien
Freiburgstrasse 634
3172 Niederwangen, Switzerland
Tel. 0041 31 328 78 45
Fax 0041 31 328 78 56