Understanding "In Vitro"

In vitro is a Latin phrase that translates to "within the glass." This term is often contrasted with in vivo, meaning "within the living." Additionally, there's in situ, which refers to "in its original place," though it is less commonly used than the former two.

To remember the distinctions between these terms, consider whether the experiment is being conducted on a living organism. For instance, a new cancer treatment may be tested on cancer cells cultivated in a laboratory (in vitro) or on a tumor within a living creature (in vivo). Typically, researchers conduct in vitro experiments first, progressing to in vivo studies only if the initial results are promising.

In situ falls in between these two, such as when examining a specific part of an organism. If we extract a cow's liver for experimentation, we are conducting an in situ study, as it lies between isolated liver cells (in vitro) and a whole living cow (in vivo).

In Vitro as a Tool for Reducing Variables

Popular culture often depicts science as beginning with a hypothesis, followed by testing to validate it. However, there are instances where we observe that something works without fully understanding the underlying mechanisms.

Often, observations guide us to conclusions without revealing the reasons behind them. For example, we might notice that individuals consuming plenty of citrus fruits tend to be healthier. Is this due to specific compounds found in oranges? The vitamins? The antioxidants? Or perhaps it's simply that eating more citrus leads to a lower intake of processed carbohydrates?

The scientific approach involves isolating variables in our experiments. Taking our citrus example, we could focus our research on a specific aspect—such as cancer. Since citrus fruits are rich in vitamin C, we could simplify the experiment by using pure vitamin C as our experimental variable.

However, it is unethical to administer vitamin C directly to cancer patients without prior evidence of its efficacy. Instead, researchers can cultivate cancerous cells in a Petri dish and expose them to high doses of vitamin C.

If this in vitro experiment shows that high levels of vitamin C kill cancer cells, we then have preliminary evidence for further investigation.

In Vivo: The Next Step in Research

Next, researchers may conduct in vivo experiments. This could involve breeding mice with cancerous tumors and then feeding them vitamin C. Here, the complexity increases significantly due to various factors:

• Does the vitamin C get absorbed effectively?
• Does it reach the cancer cells in adequate quantities?
• Are there adverse effects on healthy cells?
• What dosage is necessary to observe a significant effect?
• Is this treatment more effective than conventional cancer therapies?

Conducting in vivo experiments is often more intricate, time-consuming, and costly, which is why it is prudent to gather in vitro evidence first. While in vitro studies provide a fast and economical means of validating hypotheses, they represent just a preliminary phase on the path to real-world applications.

Key Takeaways for Non-Scientists

For those who are not engaged in laboratory research, what should you take away from the concept of "in glass," and how can this understanding enhance your scientific communication?

First, apply a healthy dose of skepticism when encountering headlines that make grandiose claims about cures or miraculous treatments. Such headlines often omit critical details about the extensive work that remains.

I have previously addressed the issue of inflated claims in cancer research.

Where’s My Damn Cancer Cure?

Every few weeks, a new article emerges touting a promising cancer drug. Here’s why we haven’t found the cure yet...

When you come across headlines asserting that a vitamin or supplement can eradicate cancer cells or extend life, check if the research was conducted in vitro or in an animal model. While many substances can eliminate cancer cells in a Petri dish, that success doesn't necessarily translate to living organisms. For instance, pouring bleach into a beaker might kill cancer cells, but it won't cure a human by submerging them in a bleach bath.

Second, comprehend that scientific progress is a step-by-step process. You can't leap straight to administering a gallon of orange juice daily to cancer patients based on initial findings. First, in vitro experiments must be conducted to minimize variables.

Then, we can advance to animal studies, where ethical considerations are more manageable. Although sacrificing a mouse is regrettable, it is preferable to prevent human fatalities from avoidable cancer.

Only after compiling substantial evidence from both in vitro and in vivo research can we consider human clinical trials. While this methodical approach might seem slow, it minimizes the risk of harmful mistakes.

In vitro—experiments conducted in isolated environments—facilitates the removal of variables, allowing researchers to design straightforward experiments. Although these studies can generate considerable hype, they are merely initial steps toward validated discoveries that can translate into real-world benefits.

Scientists often use complex Latin terminology, which can be intimidating to the uninitiated. However, gaining a better understanding of these concepts can enhance your comprehension of scientific discussions and promote critical thinking when faced with seemingly miraculous claims.

If you have any frustrations with understanding scientific content, feel free to share your thoughts in the comments!

In this insightful video, Ludovic Berthier discusses the intricacies of scientific research and the importance of clear communication in the field.

This classic demonstration showcases the principles of scientific inquiry through a candle in glass, illustrating key concepts in an engaging manner.