In Vivo and In Vitro Testing

Scientific research relies on a variety of testing methods to understand biological processes, develop new treatments, and ensure the safety of products

by | Jan 15, 2023

Lab technician pipetting blue liquid from a Petri dish

While similar, in vivo studies are done on living organisms in their natural state while in vitro tests are performed on tissues taken from living samples. | Credit: Pixabay

In vivo and in vitro testing are two of the most common methods for studying and testing organisms. While similar, each type of testing has its advantages and disadvantages. In vivo studies are those done on living organisms such as humans, animals, or even plants in their natural state rather than on samples taken from one of these living subjects. On the opposite end is in vitro testing which is done on microorganisms and tissues taken from living samples. In vitro testing is often used when studying a piece of an organism not in its natural state, such as cells or tissues in a Petri dish or test tube. This type of testing allows for a more detailed analysis of the organism being studied.

In Vivo Testing

Definition: In vivo testing involves experiments conducted within a living organism. This method provides a holistic view of biological processes as they occur in their natural context.


  • Drug Development: Evaluating the efficacy and safety of new pharmaceuticals in animal models before human trials.
  • Toxicology Studies: Assessing the impact of substances on whole organisms to determine potential risks.
  • Disease Research: Studying the progression and treatment of diseases in living systems.


  • Comprehensive Data: Provides insights into complex interactions within an entire organism.
  • Physiological Relevance: More accurately reflects how treatments or substances will behave in humans or animals.
  • Systemic Effects: Can observe effects on multiple organ systems simultaneously.


  • Ethical Concerns: Raises ethical issues related to the use of animals in research.
  • Cost and Time: Often more expensive and time-consuming than in vitro methods.
  • Variability: Biological variability can make it harder to control experimental conditions.

In Vitro Testing

Definition: In vitro testing involves experiments conducted outside of a living organism, typically in a controlled laboratory environment using cells, tissues, or organs.


  • Cellular Research: Understanding cellular mechanisms and responses to treatments.
  • Toxicology Screening: Initial screening of substances for potential toxicity.
  • Genetic Studies: Investigating gene expression and genetic manipulation in isolated cells.


  • Controlled Environment: Allows for precise control of experimental conditions.
  • Ethical Considerations: Reduces the need for animal testing, addressing ethical concerns.
  • Cost-Effective: Generally less expensive and faster than in vivo testing.
  • High Throughput: Enables screening of large numbers of samples simultaneously.


  • Limited Complexity: Cannot fully replicate the complexity of a living organism.
  • Predictive Value: May not always predict in vivo outcomes accurately.
  • Isolation: Lacks interactions with other cell types and systems present in an organism.

Integrating In Vivo and In Vitro Testing

To maximize the benefits of both methods, researchers often use a combination of in vivo and in vitro testing. This integrated approach allows for initial high-throughput screening and detailed cellular studies in vitro, followed by comprehensive in vivo testing to validate findings and assess systemic effects. By combining these methods, scientists can achieve a more thorough understanding of biological processes and develop safer and more effective treatments.


In vivo and in vitro testing are essential tools in scientific research, each offering unique advantages and insights. While in vitro testing provides a controlled and ethical environment for initial studies, in vivo testing offers the complexity and physiological relevance needed for comprehensive analysis. Together, these methods play a critical role in advancing medical and scientific knowledge, ultimately leading to better healthcare outcomes and innovations.

In vivo and in vitro test requests received by Contract Laboratory

  • FDA cGMP preclinical Contract Research Organization CRO needed for in vitro and in vivo anti-ulcer activity study of an oral solid dosage pharmaceutical drug product.
  • Toxicology laboratory needed for in vitro and in vivo toxicity testing for new chemical registration under TSCA; Toxic Substances Control Act
  • University researchers need a Contract Research Organization to conduct an in vivo study of the ability of drug products to decrease the side-effects of alcohol consumption in an animal model through neutralization of acetaldehyde.
  • Chemical toxicology laboratory
  • needed for two in vivo OECD toxicity studies of consumer air deodorizers and disinfectants supplied in Tyvek pouch. Studies must be performed on OECD 403 Acute Inhalation Toxicity of Chemicals in rodent models and OECD 402 Acute Dermal Toxicity of Chemicals in rodent models. Studies are being performed to support changes to the DOT 6.1 classification under transportation restrictions.
  • Veterinary Contract Research Organization CRO is needed for the in vivo dermatology efficacy study of OTC shampoo in the treatment of atopic dermatitis and allergic pruritis (not associated with fleas or ticks) in canine subjects.
  • A veterinary toxicology laboratory is needed for in vivo (canine) ingestion toxicity, oral toxicity, acute dermal toxicity, and dermal irritation studies on OTC topical treatment for canine atopic dermatitis. Ingestion / oral toxicity is of concern due to the potential for the animal to ingest the product after application.
  • A Preclinical Contract Research Organization CRO is needed for an in vivo osteoinductivity study of a biological product in an athymic rodent model. Endotoxin, residual calcium, and residual moisture analysis are also needed.
  • View more in vivo and in vitro test requests on our website!

Looking for a laboratory to help with your in vivo or in vitro testing or research? Contact Us to see how we can help you! Or Submit a Test Request to find a lab.


  • Trevor Henderson BSc (HK), MSc, PhD (c), is the Creative Services Director for the Laboratory Products Group at LabX Media Group. He has more than three decades of experience in the fields of scientific and technical writing, editing, and creative content creation. With academic training in the areas of human biology, physical anthropology, and community health, he has a broad skill set of both laboratory and analytical skills. Since 2013, he has been working with LabX Media Group developing content solutions that engage and inform scientists and laboratorians.

    View all posts Director, Creative Services - LabX Media Group

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