Key Difference – In Vitro vs In Vivo
Researchers perform their experiments in different experimental models. Experimental models can be of two major types; in vitro and in vivo. In vitro research runs under controlled artificial environments while in vivo research runs within the living systems at natural cellular conditions. Thus, the key difference between in vitro and in vivo is that in vitro means outside the cell in an artificial environment which is a reconstruction of the biological model whereas in vivo means within the cell under native conditions. In vitro experiments are performed in glass environments in cell-free extracts and purified or partially purified biomolecules. In vivo research is performed within living cells or organisms without manipulating the conditions.
CONTENTS
1. Overview and Key Difference
2. What is In vitro
3. What is In vivo
4. Side by Side Comparison – In vitro vs In vivo
5. Summary
What is In Vitro?
The term in vitro is used in cell biology to explain the techniques which are performed in a controlled environment outside a living cell or organism. In Latin in vitro means “within glass”. Therefore the studies which are done outside the living organism, inside glass (test tubes or Petri dishes) are known as in vitro studies. In in vitro experiments, researchers optimise the conditions very similar to cellular conditions to study the actual activities. However, in vitro experiments have less success due to the inability to provide the precise cellular conditions of the cells or the organisms under laboratory conditions.
In in vitro processes, conditions are artificial and they are reconstructions of in vivo environments. Artificial conditions are formed by mixing the necessary components and reagents under controlled conditions inside a glassware in the laboratory. Most of the molecular, biochemical experiments are carried out in vitro in the labs to test. In vitro methods are widely used in pharmaceutical industry to produce large scale pharmaceuticals using microorganisms due to its ease of production and economic benefits.
In vitro processes include PCR, construction of recombinant DNA, protein purification, in vitro fertilization, in vitro diagnosis etc.
Figure 01: In vitro cell culture
What is In Vivo?
The term in vivo refers to the experiments performed inside living cells or organisms. In Latin in vivo means “within the living”. So in in vivo experiments, conditions are not manipulated or controlled. Precise cellular conditions are present in these studies. In medicine, clinical trials and animal testing are performed in vivo to analysis overall effects of the experiments. In in vivo experiments, living cells or animal models are used. In vivo studies are crucial for the development of medical devices, surgical instruments, procedures and novel therapeutics. In clinical trials, rodents are widely used as model organisms to identify symptoms of many human diseases as their genetic, biological and behavioural characteristics closely resemble those of humans. Therefore, rodents develop similar symptoms like humans.
Compared to in vitro studies, in vivo experiments result in precise conclusions. However, since living models are complex, in vivo processes are time-consuming and labour-intensive.
Figure 02: Rabbit in Research for Animal testing
What is the difference between In Vitro and In Vivo?
In Vitro vs In Vivo |
|
| Experimental models “within the glass”. Experimental procedures performed outside the living cells are known as in vitro experiments. Such conditions are artificial conditions provided by the researcher. | Experimental models “within the living”. Experiments done within the living cell or organism are known as in vivo experiments. In vivo experiments happen under precise cellular conditions. |
| Examples | |
| Cell culture experiments in Petri dishes, experiments in test tubes, etc. are examples. | Use of model organisms such as mice, pig, rabbit, apes etc. are examples |
| Cost | |
| This is less expensive. | They are more expensive to perform. |
| Time | |
| This provides quick results. | They are time-consuming. |
| Accuracy | |
| This is less precise than in vivo experiments. | This is more precise than in vitro experiments. |
| Limitations | |
| They have fewer restrictions. | They have more restrictions. |
Summary – In vitro vs In vivo
In vitro and In vivo are two experimental models used by cell biologists to perform research. In vitro research is performed outside the living cells or organisms under manipulated research conditions inside a glassware. In vivo research is performed within living cells or living organisms under precise cellular conditions. In vivo experiments are important in animal testing and clinical trials while the in vitro experiments are useful in many cell and molecular biological studies and pharmaceutical industry.
Reference:
1. Spencer, Brandon, and Lili. “In Vitro and in Vivo.” Gene, Cell, Research, and Cells – JRank Articles. N.p., n.d. Web. 24 Feb. 2017.
2. “In vivo.” Wikipedia. Wikimedia Foundation, 17 Feb. 2017. Web. 25 Feb. 2017.
Image Courtesy:
1. “Rabbit in Research for Animal Testing” by Understanding Animal Research (CC BY 2.0) via Flickr
2. “Cell Culture in a tiny Petri dish” By kaibara87 – originally posted to Flickr as Cell Culture (CC BY 2.0) via Commons Wikimedia