Quantitative Analysis of Cell Chimerism

Since 2005 the UHKT Laboratory of Cell Chimerism has been organizing an annual proficiency testing program in the field of quantitative analysis of cell chimerism.

Each of the participating laboratories has a choice of two variants - basic and advanced. The basic variant includes 7 DNA samples, extended 12 DNA samples including: recipient_20xx (year of EPT organization), donor_20xx and another 5 (10) samples for quantification 1_20xx to 10_20xx according to the selected variant.

Aims of EPT:

  1. Informativity examination (genotyping of reference alleles) based on examination of DNA samples - recipient and donor´s DNA – 2 samples – optional part.
  2. Quantitative examination of chimerism status - 5 samples in basic variant (10 samples in extended variant) based on the chosen DNA polymorphisms and/or sex specific loci including interpretation (recipient/donor ratio) – compulsory part.

The results are compared with the expected values and based on statistical analysis using Z-score values.

Cathegory rating:

  • excellent ([z] ≤ 1) – correct result
  • good (1 ˂ [z] ≤ 2) – correct result
  • acceptable (2 ˂ [z] ≤ 3) – correct result
  • critical ([z] > 3) – incorrect result
  • under detection limit of the laboratory (the sensitivity of the participant's method is not able to detect the minor genotype – the example: the expected value of minor genotype is 0.2% and the participant with the sensitivity of 1% determines the detection of only the majority genotype - this result is considered to be correct. But if the participant detects both genotypes and quantifies it, the result is evaluated by Z-score.

To achieve an acceptable performance of EPT, at least 80% success rate is required (that is 8/10 samples in the extended variant, 4/5 samples in the basic variant).

In case of interest an additional round will be announced. In this round, five quantification samples will be sent.

Guarantor: Mgr. Lucie Stefflová (

Quick contact

Head of the Lab Complex
Tel:+420 221 977 208
Fax:+420 221 977 208

Deputy Head of the Lab Complex
Tel:+420 221 977 263

Opening hours

Mo – Fr: 7:00–18:00
Weekends: 9:00–13:00

Mo – Fr: 7:00–10:30

Inpatient department
Mo – Fr: 13:00–18:00

ICU and Transplant unit
Mo – Fr: 14:00–17:00

How to find us


Ústav hematologie a krevní transfuze
(​Institute of Hematology and Blood Transfusion)

U Nemocnice 2094/1
128 00 Praha 2

The nearest underground station: Karlovo náměstí (line B)

The nearest tram station: Karlovo náměstí (10, 16, 22), Moráň (3, 6, 10, 16, 18, 24)

The nearest bus station: U Nemocnice (148), Karlovo náměstí (176)

How to get here