These two are more commonly used scientific terms. These terms are often used in assisted reproduction technologies as well as in the scientific domain. It helps to know what these terms stand for.
Both these terms are derived from Latin words. In Latin, in vitro denotes “in the glass” and in vivo refers to “in the living or being”.
In vivo comprises of tests done on the whole being with life in it. It contrasts from tests done on samples or dead cells. Many of the drug testing is done through in vivo methods. Such tests include tests done on animals as well as clinical trials done on human beings.
In vitro isolates a sample from an organism. This is done to perform more in-depth studies and assess the components in closed conditions. These are also termed as experiments done with test tubes. In vitro differs from in vivo in not exposing living beings into real risks associated with the adverse or harmful effects of experimentation.
In scientific studies, the new drug or a chemical is first tested through in vitro modes before being exposed to living beings. Once after the substance under test passes a threshold of safety, it is then exposed onto humans and animals alike.
The 8 best differences between in vivo and in vitro
There are some glaring differences between these two methods.
#1. In vivo needs to pass through various rules and regulations. This is because in vivo tests may put living beings to risks. It is to avoid these risks, each in vivo test needs to clear various procedural requirements.
#2. In vivo tests can lead to results with greater levels of accuracy. This is due to its ability to conduct the experiment in live conditions and in situations that mirror active life itself.
#3. In vivo studies are far more costly than in vitro tests.
#4. The time taken for in vivo experiments is also on the higher side as compared to in vitro tests.
These two methods are commonly used in the discovery of new molecules and newer procedures to treat medical conditions. Also, in drug discoveries and testing of new drugs both these approaches are increasingly used.
#5. In vitro experiments are carried out to infer allergy tests and sensitivity to specific drugs. Such experiments help to decide treatments to be pursued in case of contagious diseases.
#6. A petri dish with cells from a living organism is added with a drug to be tested. The cell’s reactions to the new drug are closely observed through clinical procedures. If the tests reveal no safety related issues, then the tests are taken to in vivo mode. However, scientists are aware that in vitro tests do not mirror real life situations and hence may pose limitations on how in vitro-tested drugs react on a living organism.
#7. The in vivo tests are first carried out on animals. Rats are the most commonly used specimen used for animal testing. The outcomes of the new drug on rats are a first level indicator on the drug’s safety as well as efficacy. However, animal testing also poses a few inherent limitations and risks. The most apparent limitation is, the drug may appear safe on the animal but may trigger adverse and harmful side effects while put to use on humans. Hence, animal testing is not a conclusive approach to state that a drug is safe on human beings.
Once clearing the in vivo tests done on animals, the tests are taken to humans. The main objective of these tests is to ensure safety of the tested humans. Additional goals include how to isolate the effects of the new drug from a possible placebo effect. Placebo has no curative or therapeutic value but the patients may assume that the drug has offered a relief to their pain or another symptom.
#8. All in vivo tests administered on humans are done on voluntary basis and can be stopped at any point in time based on the discretion of the patients.
In vitro fertilization
In vitro fertilization is a popular method used as an assisted reproductive technique. In this procedure, your eggs are taken from the ovaries. Sperm from your partner is used to fertilize eggs sourced from your ovaries. Once fertilization occurs, the embryo is then placed inside your uterus. This is a popularly adopted technique to make women conceive. Infertility related problems are affecting a bigger number of couples, and in vitro fertilization is a common approach to make them have babies.
So, both in vitro and in vivo are widely used in biopsies, drug related tests, etc. Both have unique advantages as well as a few disadvantages. Given their inherent limitations, clinical researchers often use both types of tests to reach their final results.