Carla Zijlstra was trained as a biologist at the "Vrije Universiteit" Amsterdam. After her PhD study in Leiden, she obtained a post-doc position at the department of Functional Morphology at the Faculty of Veterinary Medicine, at Utrecht University in 1991. She participated in the European Pig gene mapping project and was trained in cytogenetics of different animal species (including pig, rabbit and dog) by dr. A.A. Bosma.

In 1998 she was appointed as an assistant professor at the department of Cell Biology at the Faculty of Veterinary Medicine Utrecht. Since then her research focussed on reproduction in a broad sense.  She participated in studies on gene expression in porcine granulosa cells, aneuploidy in in vivo and in vitro produced porcine embryos, hermafroditism in dogs and oocyte maturation in C.elegans. In 2013 she started a collaboration with W. Stoorvogel on the characterization of small RNAs present in extracellular vesicles isolated from semeninal fluid. The aim of this collaboration was to find biomarkers for the diagnosis of prostate cancer. Carla has experience in many techniques, including cell culture, karyotyping, immunocytochemistry, FISH, Western blotting, (q)PCR, next generation sequencing.

Since 2019 her main focus is on teaching histology to bachelor Veterinary medicine students. She developed several digital microscopy modules using the interactive program PathXL.