Biological research has an age-old debate about which buffer to use for biological experiments, specifically immunohistochemistry (IHC). The two most used buffers are Tris Buffered Saline (TBS) and Phosphate Buffered Saline (PBS). Though they might seem interchangeable, there are crucial differences that can impact the results of an experiment. Before diving into these differences, it is necessary to define what PBS and TBS are:
- PBS: A salt solution containing sodium chloride, sodium phosphate, and, in some formulations, potassium chloride and potassium phosphate.
- TBS: A saline solution buffered with tris(hydroxymethyl) aminomethane (Tris), a widely used biological buffer containing sodium chloride.
Both buffers are used to maintain the pH and osmolarity of the solution, which is critical in preserving tissue morphology and protein integrity. However, their unique properties make them suitable for different scenarios in IHC.
The Roles of PBS in IHC
- Cell and Tissue Preservation: PBS is isotonic and non-toxic, making it ideal for preserving cell structure and tissue morphology.
- pH Stability: It offers excellent pH stability, crucial for antigen-antibody reactions.
- Versatility: PBS is often used as a washing buffer between steps in IHC to remove excess antibodies and reagents without disturbing the tissue sections or the bound antibodies.
The Role of TBS in IHC
- Reduced Background Staining: TBS can reduce nonspecific background staining, a common challenge in IHC. This is particularly true for tissues with higher endogenous peroxidase activity.
- Buffering Capacity: TBS has a higher buffering capacity than PBS, which can be advantageous in maintaining a stable pH during longer incubation times or under varying temperature conditions.
- Compatibility with Detection Systems: Some detection systems, especially those using horseradish peroxidase (HRP), may perform better with TBS.
Choosing Between PBS and TBS
The choice between TBS and PBS in IHC is not just a matter of personal preference but should be based on the specific needs of the experiment:
- Antigen Characteristics: Some antigens may show better staining with one buffer over the other.
- Tissue Type: One buffer might reduce background staining more effectively depending on the tissue’s nature and the presence of endogenous enzymes.
- Antibody Type: The choice can depend on the primary and secondary antibodies used. Some antibodies may have optimized protocols recommending either TBS or PBS.
Both PBS and TBS play vital roles in the success of an IHC experiment. The key is understanding each buffer’s nuances, and how they interact with your specific IHC protocol. Here at Visikol, we put forth our best efforts to understand your tissue type and experimentation needs, working diligently with any client’s experiments to determine the best buffer for your application. As always, following protocol guidelines and leveraging published research can guide you in making the right choice for your IHC needs.
If you’re interested in working with Visikol on an upcoming project, please reach out to a member of our team today.