Tissues are made of groups of cells that work together to perform specific functions. There are different types of tissues, each with its own unique role, such as:
- Epithelial tissue: Forms the outer covering of the body (skin) and lines internal organs, glands, and cavities. These tissues help in protection, absorption, secretion, and filtration.
- Muscle tissue: These tissues are responsible for the movement of the body. Muscle tissues include skeletal muscles, cardiac muscles, and smooth muscles.
- Connective tissue: These tissues provide support, structure, and connection between the tissues and organs. They help in structural support, transport of substances, energy storage, and defense.
- Nervous tissue: These tissues are found in the brain and spinal cord. They help sense stimuli, process sensory information, and control body responses.
However, infections, physical injury, lack of oxygen, exposure to chemicals, toxins, and radiation, chronic inflammation, autoimmune responses, nutritional deficiencies, and aging can damage the cells in tissues over time and disrupt the normal functioning of tissues. This can further lead to various diseases in the body, including arthritis, asthma, inflammatory bowel disease, cancer, liver cirrhosis, cardiovascular disease, Alzheimer’s disease, diabetes, and etc.
That is why tissue study is important. This helps researchers and scientists to:
- Understand disease at the cellular level
- Accurately diagnose a disease
- Detect infectious agents in the body
- Identify biomarkers
- Evaluate treatment response
- Develop and research new drugs
In order to study tissues, researchers and scientists rely on the Immunohistochemistry (IHC) technique.
What is Immunohistochemistry (IHC)?
Proteins are the building blocks of cells. They act as enzymes, receptors, and signaling molecules that regulate how tissues work. The type and amount of proteins present in a tissue determine its condition.
For instance, healthy tissue expresses proteins in a normal pattern, whereas diseased tissues may show overexpression, underexpression, or abnormal proteins. So, scientists study these proteins to understand disease using techniques like IHC.
Immunohistochemistry (IHC) is a laboratory technique used to detect specific proteins in tissue samples. This technique relies on the specific binding of an antibody to its antigen within a tissue sample. This antigen is usually a protein of interest, and the antibody is designed to recognize and attach to it.
IHC helps:
- Reveal protein expressions
- Show spatial distribution
- In diagnosis
- Connect molecular biology with tissue structure
In this technique, a thin section of tissue (from a biopsy or experimental study) is placed on a slide and treated with antibodies. These antibodies bind to specific proteins (antigens) within the tissue.
To visualize this binding, the antibodies are linked to a label such as an enzyme or a fluorescent dye. When observed under a microscope, these labels reveal the exact location and distribution of the target proteins within the tissue.
| Note: Researchers use polyclonal antibodies (pAbs) in the IHC technique to detect the presence of proteins in the sample. Polyclonal antibodies are a heterogeneous mixture of antibodies produced by different B-cell clones in the body. Each antibody in this mixture recognizes and binds to a different epitope (binding site) on the same antigen. So, these antibodies have high: -Sensitivity -Flexibility -Versatility -Ability to produce a strong signal, even if the amount of protein is very low. |
How pAbs Aid in IHC and Tissue Studies?
Detect Low-Abundance Proteins
In many diseases, certain proteins are expressed in very small quantities. Since pAbs bind to multiple sites on the same protein, they generate a stronger signal compared to monoclonal antibodies. This high sensitivity makes them especially valuable in the early detection of disease markers in tissues.
Overcome Antigen Masking
Tissue samples are usually treated with fixation and embedding techniques to preserve their structure. These processes can sometimes alter or mask epitopes. As a result, they are less recognizable to antibodies. However, pAbs can recognize several epitopes on the same antigen. So, they are still able to bind effectively and aid in accurate detection.
Versatile in Nature
Polyclonal antibodies are effective in a wide range of applications, not only in IHC but also in techniques such as ELISA, Western blotting, and flow cytometry. Their ability to detect proteins across species and tissue types makes them highly versatile for both diagnostic and research purposes.
Strong Signal Amplification
Since multiple pAbs can attach to different sites on the same protein, the overall staining intensity in IHC is amplified. This results in clearer images of protein localization within tissue samples. This allows researchers to map disease progression or response to treatment.
Applications of pAbs in Tissue Research
pAbs help understand both normal physiology and disease pathology using the IHC technique. Here are common applications of pAbs in tissue research:
- Cancer research and diagnosis: pAbs help detect tumor markers, such as hormone receptors, growth factors, and abnormal proteins, expressed in cancer tissues. This aids in accurate diagnosis, tumor classification, and informed therapeutic decision-making.
- Infectious Disease Studies: By targeting microbial antigens, pAbs allow researchers to localize bacteria, viruses, or fungi in infected tissues.
For instance, when Influenza A infects lung tissue, it expresses viral proteins such as nucleoproteins and hemagglutinin within host cells. At times, scientists use rabbit influenza A polyclonal antibody to detect viral proteins in infected tissues using IHC.
Because the antibodies recognize multiple epitopes on the viral proteins, they produce a robust staining signal, even when viral protein levels are low.
This allows scientists to track how the virus spreads within lung tissue, study tissue damage caused by infection, and evaluate the effect of antiviral drugs.
- Neurological Disorders: In brain tissue studies, pAbs are used to detect proteins such as tau or amyloid-beta, which are linked to Alzheimer’s disease and other neurodegenerative conditions.
- Biomarker Discovery: pAbs are frequently used in early stages of biomarker research to validate whether candidate proteins are present and detectable in tissues.
The Bottom Line
Now that you know how pAbs aid in IHC and tissue studies, what are you waiting for? Find a reliable supplier who can provide you with high-quality polyclonal antibodies online to support your experiment and research now!
This article was written for WHN by Cynthia Lee is the President of AAA Biotech (AAA Bio / AAABio), a company specializing in highly validated and characterized monoclonal/polyclonal antibodies, recombinant proteins, and ELISA kits.
As with anything you read on the internet, this article should not be construed as medical advice; please talk to your doctor or primary care provider before changing your wellness routine. WHN neither agrees nor disagrees with any of the materials posted. This article is not intended to provide a medical diagnosis, recommendation, treatment, or endorsement.
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