3R’s of animal experiments

Replace – Animal experiments are only approved if no other suitable alternative exists such as through cell cultures and computer models

Reduce – The number of animals used in experiments is reduced to the absolute minimum to achieve meaningful and representative results.

Refine – Experimental conditions as well as animal housing during experiments is to always be optimized where possible and the most animal-friendly experimental set-up chosen.


A spheroid is an aggregation of cells into a round cell cluster that is a three-dimensional in structure. An anti-adhesive surface is helpful for the formation of round and uniform spheroids. Spheroids can form with a variety cell types such as primary cells or immortalized cell lines.


Unlike a spheroid that is a simple assemblage of cells, an organoid is a complex cluster of cells. The assembled cells are organ specific such as liver cells and self-assemble into an ordered structure. Depending on the growth environment they will differentiate into microscopic versions of the organ that can be used in 3D studies and is the basis of organ-on-a-chip.

3D vs 2D

Artificial 2D culture systems recapitulate the in vivo conditions only insufficient which impacts cells behavior and predictability of experiments. When growing cells in a 3D environment it better mimics the natural environment making research more reliable.

Scaffold-based vs. non-scaffold-based

Non-scaffold-based research relies on the cells to create and uphold the structure such as spheroids on their own. In scaffold-based research an artificial structure such as with a fiber structures provides the backbone structure for the cells.

High throughput screening (HTS)

HTS is a method automatically and rapidly test a large number of samples for biological activity for examples. This method is restricted to specific lab ware formats usually 96- to 1536-well plates. However, it is a rapid way to screen properties such as concentration and response curves.