The serum is one of the important aspects of cell culture. However, there has been a score of discussions on their advantages and disadvantages. This article elucidates the role of serum and how should we avoid it.
The most important component of cell culture is likely the culture medium, and years of experimentation have yielded a variety of media compositions and commercial media formulas. Fetal bovine serum is ordinarily employed as a serum supplement in cell growth media. However, do you understand the significance of adding this and, more crucially, can your cells survive without it? We go through the advantages and disadvantages of utilising serum in cell culture media as well as how to get rid of it if you wish to do so.
What Role Does Serum Play in Cell Culture?
To keep your cells healthy, the culture medium contains vitamins, carbohydrates, and buffering agents. And you frequently add serum, like FBS. Since it includes hormones, lipids, and growth factors that are crucial for cell proliferation and growth, this is one of the key components of cell culture media.
If you take the serum out of your culture medium, you will see a significant difference. When intentionally starving your culture of serum, you can induce cell cycle synchronisation, but be cautious as doing so too long will also limit cellular proliferation and enhance apoptosis.
Why Should You Think About Avoiding Serum?
Although serum helps keep your cells healthy and thriving in cell culture, there are some significant drawbacks.
1. Serum Variability Is High
Well, first of all, the serum is a natural substance made from animal sources, and every fresh batch will be unique. Although serum does include elements that are crucial for the well-being of your cells, it also includes elements like immune complement proteins that might damage your cells. The serum is typically boiled to inactivate toxic proteins as a workaround. Naturally, heat will also denature helpful proteins, which may lead to greater differences in media preparations.
Even though this might not be a major problem for some forms of research, if you are conducting, for instance, a cell-based assay to determine the impact of a growth factor or drug on specific cell processes, the variability in factors that are crucial for cell survival and proliferation can skew your results.
2. Standardization of Culture Media
In this instance, standardising culture conditions for more predictable and reproducible outcomes is one of the main justifications for going serum-free. In controlled laboratories, this kind of standardisation is even more important, and having a predetermined medium gives you more command over your cell culture and your investigations.
3. Serum may contain contaminants.
Viral or bacterial contamination of serum used in cell culture is another potential problem. Once more, there can be variation from lot to lot, and heat inactivation may not completely destroy microbial pathogens. Your cells' health and growth will be impacted by polluted serum, making them useless for experimentation.
4. Serum Is a Product of Animals
Supporting the improvement, decrease, and substitution of the use of animals or animal products in research—is still another factor for turning serum-free.
What Are the Drawbacks of Avoiding Serum?
Perhaps you have decided that conducting your cell culture studies without serum is the best course of action. Finding the ideal combination of growth elements to sustain your culture is among the swap, but this is true of many scientific endeavours.
Different types of cell lines have unique and complex growing requirements. The ideal culturing conditions can even vary between cell passages! You will have a difficult task ahead of you if you include primary cultures or cultures that are in suspension. Thankfully, you are not alone and there is a tonne of reliable resources available online to help you. Additionally, many culture media producers have created particular serum-free formulations for common immortalised cell lines.
Going serum-free has a number of disadvantages, including slower cell development and cell clumping during passaging, in addition to the challenge of creating the ideal circumstances. Continued improvement of the culture conditions can aid in reducing the pace of growth, and gentle repeated pipetting of cell clumps should be sufficient to spread them out.
How to Avoid Serum?
After discussing the advantages and disadvantages of going serum-free, let's look at how to accomplish it in real life. Be aware that while some cell types can be grown with no serum at all, others will require the addition of other components to the media to fill the place of the missing serum.
We can summarize that serum is a real boon for the growth of almost any cell line. But when it comes to getting high yields and quality of cells, the choice of serum has a significant role to play. Even a small switch could make a huge difference in your experiment.
It can be concluded from the above discussion that serum is essential for the growth and development of cells. It reduces the side effects of cancer and helps in increasing immunity. However, there is a drawback to having them; they are usually unspecific factors and thus may trigger immune reactions. Serum should therefore be replaced by other safer components that entice cells to grow in culture.
There are different types of serum available in the market. It is an easy task to serially dilute 1x, 2x and 3x and make four different lots for freezing. However, there is a need to serial dilute each vial and store them separately, as different lots may have different properties due to changes in the original components during handling and storage. For this application, serum may be used unconditionally especially if its lot-to-lot variability is constant for a long time. However, for applications such as the differentiation of stem cells into specific cell lineages, this requires a better standardization strategy.
