Professor Dr. Cornelis (Kees) Kluft

Prof. Dr. Kluft is the founder and CEO of GBS Leiden, and a renowned expert in haemostasis and human biomarkers. He was projectleader of projects of several large pharmaceutical companies, as well as different academic research organizations and charitable foundations supporting patient groups.
He started his career in haemostasis (fibrinolysis) at TNO (Nederlandse Organisatie voor Toegepast-Natuurwetenschappelijk Onderzoek) in 1972. Continuing as TNO’s Haemostasis specialist and division head of vascular medicine and connective tissue research and was one of the founders of TNO Pharma. He is chairman of the supervisory board of ECAT, external quality assessment organisation. He previously held positions as Professor in Thrombosis Research (University of Southern Denmark) and in Cardiovascular Biology (Catholic University, Italy).
After 33 years he left TNO, started GBS and continued working with the CHDR (Centre for Human Drug Research) as a biomarker specialist. Presently, he is also visiting professor at the University of Southern Denmark in Esbjerg University, in a joint programme on biocompatibility and contact activation.

Tel:      +31 (0)6 53 62 22 21


Dr. Dimitar Tasev, MD

Dimitar Tasev  is the Scientific officer at GBS specialized in functional cellular assays in the field of immunity, inflammation, neurodegeneration, stem cell and vascular cell biology.

He was educated and worked as an MD in Macedonia until 2009 when he moved to the Netherlands to pursue an MSc degree in Biomedical Sciences. During the two one-year research specializations in Advanced Immunology and Cardiovascular Research, he investigated the immunological aspects of multiple sclerosis and the role of endothelial progenitor cells in angiogenesis. Prior to his current position, he investigated the biological response of endothelial progenitor cells to hypoxia and inflammation in 3D matrices during angiogenesis as a PhD student at ICaR-VU, VUmc, Amsterdam. In the course of his stay in academia, he obtained broad knowledge of molecular biology techniques, cell culture, tissue engineering and assay development.

Tel:      +31 (0)71 751 71 74


Dr. Petra de Kruijf, PhD

Petra de Kruijf is the laboratory coordinator and scientist at GBS.

She started her career in 2007 as PhD-student at the VU university in Amsterdam at the department of Medicinal Chemistry. Her PhD-project focused on the chemokine receptor CXCR2 (a GPCR), which is expressed on several immune system cells and plays an important role in chronic inflammatory diseases like COPD, IBD and psoriasis. She has investigated the interaction of chemokines and small synthetic ligands with this receptor. After her PhD in 2012, she became a biochemical project leader in the group of biochemical support production at Sanquin Plasma Products in which she was the product expert of the coagulation factor products (FVIII, FIX and PCC) and a C1-esterase inhibitor. Daily worked involved: supervision of people, writing product impact assessments related to deviations, setting up downscale experiments, outsourcing virus validation studies, coordination of process performance qualifications runs and managing follow-up of inspections. Next, in 2017 she became head in the support department of Quality Control at Sanquin Plasma Products. She was responsible for the reference standards and control samples, consumable management for the lab and the complete stability program of Sanquin Plasma Products.

Tel:      +31 (0)71 751 71 71