Should animals be used to test medical products?

This is a debate that researchers and scientists alike are constantly confronted with. On the one hand, these animals can feel pain and aren’t perfect replicas of our anatomy as humans. On the other hand, the models of some animals (ex. mice 🐭 and monkeys 🐵) are close enough to people and allow us to develop effective treatments (ex. antibiotics, insulin, vaccines 💉) against many diseases.

This debate, like many others, doesn’t have a correct answer. However, a compromise has been reached in form of the 3Rs: reduce, refine, and replace. The 3Rs act as principles that researchers follow to lessen the harm done to animals.

For now, let’s focus on ‘replace’. The figure above states that an example of the replace principle is cultured cells. Cultured cells are grown in vitro (outside a living organism, inside a dish or test tube) by humans. Scientists can modify these cells to carry out their experiments.

On paper, this sounds like a great solution to our ethical problem. We don’t need to physically harm the animals when we can make cells!

Well, let’s dive a bit deeper. These cultured cells need a culture medium from which they can reproduce. So what’s the main medium being used today?

FBS, also known as Fetal Bovine Serum 🐮.

If that name didn’t already raise some red flags, FBS is a byproduct of the meat industry. When pregnant cows are slaughtered, blood is extracted from the embryo (the unborn calf). The liquid that remains is used for FBS.

Why is FBS Widely Used?

There are a variety of reasons that FBS is the number one culture medium. To make this easier to digest, I’ll be dividing this section into two subsections: scientific and economic.

Scientific

FBS is typically used in only 2–10% of the culture medium, though this number varies based on what kind of cells are being cultured. But this portion contains many vital growth factors, such as hormones, nutrients, and sugar. FBS also contains fewer growth-inhibiting factors 

Economic

The bulk of the benefits of FBS lie within the scientific section, but there are still a couple of benefits on the economic side of things.

As I mentioned before, FBS is a byproduct of the meat industry. This makes FBS quite easy to produce. As long as you have pregnant livestock, you can get yourself some FBS. It’s also an effective way to make a quick buck 🤑. Not only are you manufacturing your meat products, but you’re also selling the leftovers — a win-win situation.

What is the Best Alternative to FBS?

To answer that question, we have to lay out some criteria. The ideal FBS replacement should:

• Have consistent batches and availability
• Increase and assist the growth of cultured cells
• Be compatible with a variety of cells
• Reduce or avoid harm to living organisms

I’ll be comparing bovine ocular fluid, fish 🐟 serum, sericin protein, human platelet lysate (HPL), and earthworm heat inactivated coelomic fluid (HI-CF).

Bovine Ocular Fluid

Bovine ocular fluid, like FBS, is a byproduct of the meat industry. It’s gathered from the eye 👁 of a slaughtered cow. Since the cow is already dead when the fluid is collected, bovine ocular fluid is already a step ahead of FBS.

Bovine ocular fluid contains the same desirable growth factors that FBS has. It can also speed growth rates and help the growth of WISH (Wistar Institute Human Amniotic Cells), Human Bone Marrow Fibroblasts, and Vero cells (Vervet Monkey Kidney) better than FBS can.

Unfortunately, there isn’t enough bovine ocular fluid to meet the demand that FBS created.

Fish Serum

Fish serum, as you might guess, comes from fish and is a byproduct of the fish industry. Like FBS, this allows fishers to a) produce fish serum with ease and b) earn some extra money💰.

But fish serum has one big issue that contradicts the criteria — it isn’t consistent. Fish serum suffers from varying batches, which pretty much makes it ineligible as a replacement for FBS.

Sericin Protein

Sericin protein is a byproduct, not of the meat industry, but silk harvested from a silkmoth’s cocoon. This protein naturally increases cell proliferation due to certain amino acids.