The use of cell cultures in testing, or assays, isn’t new. It consists of trying out substances on cells grown in vitro and studying their positive or negative effects.
Cell culture assays don’t require the sacrifice of guinea pigs, aka living test subjects, and can be carried out on human cell tissues. Today there is a huge bank of human tissues collected humanely and anonymously. The use of human tissue provides relevant results as humans are the recipients of the product.
This gives results as though multiple tests were carried out on the same individual without the risks of making it ill, modifying its reactions or even killing it.

As the cells are identical, the variations can only come from the product being tested.
On the same cells, it is also possible to test not only the target products but also a combination of them. As the production of cell cultures is so cheap, a wide variety of cocktails can be tested to discover any new interactions.
A substance introduced into the body will circulate into all tissues and may have different effects on each of them. Indeed, despite having the same genetic origins, our cells are specialised and work differently according to the tissue it is made of.
The use of cell cultures of different organs or tissues gives specific information regarding the reaction of each cell type.

Whilst the cell cultures allow us to observe the effects of a substance at the organ level, it doesn’t allow us to assume the overall effects on the organism. This is usually the argument used for the promotion of animal testing.
To gain an overall view of the organism, the passage of the test substance through successive organs can be simulated. The liver is a key organ in the metabolism as it transforms molecules therefore the following procedure can be used:
We then have the results from a variety of tissues to the substance which has been metabolised by the liver.

Today, techniques such as microdosing or microfluidic biochips allow us to study the effects of a product on the organism far more in depth.
