Determination of cell concentration is one of the most frequently requested quantities to support medical diagnostics and therapy. Lack of higher order reference methods and materials is a major hindrance for deriving traceability and measurement comparability. The EMRP-Project BioSITrace 'Traceability for biologically relevant molecules and entities' develops such procedures and materials for the enumeration of nucleic acids, lipoproteins and cells. The work package lead by PTB develops and evaluates primary procedures based on flow cytometry and microscopy. A secondary reference procedure along the traceability chain can be based on relative enumerations of the target cell concentration to a calibrator concentration. The application of such procedures will allow manufacturers and end users on-site assessment of the performance of their instruments and protocols.

The research activities will also feed in national and international standardisation at DIN and ISO.
ISO 20391-1:2018(en)
Biotechnology — Cell counting — Part 1: General guidance on cell counting methods

ISO 20391-2:2019(en)
Biotechnology — Cell Counting — Part 2: Experimental design and statistical analysis to quantify counting method performance

ISO 20395:2019(en)
Biotechnology — Requirements for evaluating the performance of quantification methods for nucleic acid target sequences — qPCR and dPCR

ISO/TS 5798:2022(en)
In vitro diagnostic test systems — Requirements and recommendations for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by nucleic acid amplification methods

JCTLM Database:

C3RMMP34
PTB reference method for blood cell counting, thrombocyte (for lower particle concentration)

C3RMMP35
PTB reference method for blood cell counting, thrombocyte

C16RMP1
PTB reference method for blood cell counting, erythrocyte

1. Neukammer J, Kammel M, Höckner, J, Kummrow A, Ruf A.
Reference Procedure for the Measurement of Stem Cell Concentrations in Apheresis Products
PTB-Mitteilungen 125 No2  (2015) 70-73,  English translation of the original version:
Neukammer J, Kammel M, Höckner J, Kummrow A, Ruf A.
Referenzverfahren zur Messung von Stammzellkonzentrationen
BIOspektrum 03.15, (2015) 294-297, ISSN 0947-0867

2. Kammel M, Kummrow A, John M, Reitz S, Witt K., Neukammer J.
Flow cytometer for reference measurements of blood cell concentrations with low uncertainties
IEEE Transactions on Instrumentation and Measurement (TIM) : Special Issue of IEEE International Symposium on Medical Measurements and Applications (2015), Turin, 09, April, 2015

3. Kammel, M.; Kummrow, A.; Neukammer, J.
Reference measurement procedures for the accurate determination of cell concentrations: present status and future developments
J. Lab. Med. 36 (2012) 25-34.

4. Stebbings R, Wang L, Sutherland J, Kammel M, Gaigalas AK, John M, Roemer B, Kuhne M, Schneider RJ, Braun M, Engel A, Dikshit D, Abbasi F, Marti GE, Sassi M, Revel L, Kim SK, Baradez M, Lekishvili T, Marshall D, Whitby L, Jing W, Ost V, Vonsky M, Neukammer J.
Quantification of Cells with Specific Phenotypes I: Determination of CD4+ Cell Count Per Microliter in Reconstituted Lyophilized Human PBMC Prelabeled with Anti-CD4 FITC Antibody
Cytometry A 87A (2015) 244-253