Biological specimens

What Is a Biological Sample? An Overview

Explore Biological Samples: Definitions, Examples, and Their Crucial Role in Research and Classification. Learn more!

Image Description
Peace Chikezie

Published 22 Sep 2023

What Is a Biological Sample? An Overview - Infiuss Health


What if we lived in a world with no medical progress, where diseases couldn't be treated properly? 

Fortunately, this is not our reality, thanks to biological specimens. 

In this blog, we'll explain the concept of biological specimens, exploring what they are, their various examples, and why they are vital in advancing medical knowledge and improving human health.


What is a Biological Specimen?

At its core, a biological specimen is any material that originates from a living organism's body that can be studied and analyzed in a lab.

Human biological specimens are any materials that come from the human body.

These specimens can be collected for research purposes or as leftovers from medical tests, procedures, or surgeries.

They often offer vital insights into health, disease, and medical research.


Examples of Biological Specimens from the Human Body

Human biological specimens come in various forms or typesand you might be surprised by the range of materials that qualify.

Here is a list of 10 specific examples of biological specimens from the human body.

  1. Blood, Plasma, and Serum
  2. Cells (e.g., RBC, WBC, etc.)
  3. Tissue  
  4. Urine
  5. Saliva
  6. Semen
  7. Feces/stool
  8. Bone Marrow 
  9. DNA/RNA.
  10. Hair, Skin, Nails


Let's briefly discuss the relevance of each.


1. Blood, Serum, and Plasma

These are perhaps the most recognizable and are the cornerstone of medical diagnostics. 

They allow us to identify diseases, monitor treatment effectiveness, and assess overall health.

2. Cells (e.g., RBC, WBC, etc.)

Different types of blood cells, such as red blood cells (RBCs) and white blood cells (WBCs), help diagnose anemia, infections, and blood-related disorders.

3. Tissue

Tissue specimens allow researchers to delve deep into understanding disease development and progression, enabling the development of new treatments. 

For example, skin biopsies can help diagnose skin conditions such as melanoma, skin cancer, autoimmune diseases like lupus, and others

4. Urine

Often used to assess kidney function, diabetes, and even pregnancy, urine specimens are relatively easy to collect.

5. Saliva

Non-invasive and rich in biomarkers, saliva specimens are a treasure trove for researchers studying various diseases.

Saliva specimens have gained significant attention, especially during the COVID-19 pandemic. This method has proven highly effective in detecting the presence of the SARS-CoV-2 virus, which causes COVID-19.

6. Semen

Used for medical testing, criminal investigations, and assessing fertility, semen specimens have diverse applications.

7. Feces/Stool

These specimens help analyze the microbiome, diagnose gastrointestinal disorders, and assess diet and metabolism.

8. Bone Marrow

Critical for studying blood disorders and generating stem cells for transplantation.


Genetic material extracted from biological samples allows for genetic testing and the identification of genetic markers related to diseases.

10. Hair, Skin, Nails

These specimens, though seemingly ordinary, can provide essential information about conditions like dermatological diseases and nutritional deficiencies.

Other examples include fluid specimens from areas like the pleura, synovial joints, and cerebrospinal fluid (CSF). They can assist in diagnosing conditions such as pneumonia, arthritis, and neurological disorders.

Each biological specimen has its role to play in our quest for better healthcare and scientific understanding.


How to Classify Human Biological Specimens

Classifying human biological specimens is a crucial step in organizing and managing these valuable resources for medical research and diagnostic purposes. 

Proper classification ensures that specimens are easily accessible, identifiable, and used effectively. 

Here's how human biological specimens are typically classified:

1. Type of Specimen

The first classification criterion is based on the nature or type of the specimen itself. This includes categorizing specimens as blood, urine, tissue, saliva, CSF, semen, feces, and others. Each type has its unique properties and relevance in research and diagnostics.

2. Source of Origin

Specimens can be classified by their source or origin, such as whether they are derived from patients, healthy individuals, deceased people, specific age groups, or patients with particular medical conditions. This helps researchers select the most suitable specimens for their studies.

3. Clinical Diagnosis

Specimens may also be classified based on the clinical diagnosis or purpose of collection. 

For example, specimens collected for cancer research, infectious disease studies, genetic testing, or autoimmune disorders may be categorized separately to streamline research efforts.

4. Collection Method

The method of specimen collection is another classification criterion. Some specimens require specific collection procedures, such as biopsies for tissues, venipuncture for blood, or swabs for saliva. 

Specimens obtained through various techniques may be grouped accordingly.

5. Storage Conditions

Classification also takes into account the storage conditions required for different specimens. 

Some specimens need to be frozen, while others are stored at room temperature or refrigerated. 

Proper categorization ensures that specimens are stored appropriately to maintain their integrity.

6. Ethical Considerations

Ethical aspects play a significant role in specimen classification.

Specimens obtained with informed consent, those collected from deceased individuals, and those with specific privacy considerations may be categorized separately to ensure best practices in ethical use.


Frequently Asked Questions 

1. What is the difference between a sample and a specimen?

Sample: A sample is a general term for a small portion or subset of a larger material, often taken for analysis or testing. It can refer to various substances, including biological materials.

Specimen: A specimen, on the other hand, is a specific type of sample, typically referring to a biological material or substance that is collected and preserved for scientific examination, research, or diagnostic purposes. Specimens are often more rigorously collected, handled, and documented due to their importance in research and healthcare.

2. What are specimen containers?

Specimen containers are specialized containers designed to securely hold and transport biological specimens, such as blood, urine, tissue, or other bodily fluids. These containers are designed to prevent contamination, and leakage, and maintain the integrity of the specimen until it reaches a laboratory for analysis.

3. What are human tissue samples for research?

Human tissue samples for research are small portions of human tissues (e.g., skin, muscle, or organs) collected from individuals for scientific investigations. These samples are used to study diseases, develop treatments, and gain insights into the functioning of the human body at the cellular and molecular levels.

4. Why are specimens cut before tissue processing?

Specimens are often cut or sectioned before tissue processing for various reasons, including standardization and efficient analysis. Cutting allows for uniform preparation, ensuring that different parts of the tissue can be examined consistently. It also facilitates embedding in paraffin blocks for microscopic analysis.

5. Can a specimen collector tamper with a person's sample?

Specimen collectors are bound by strict ethical and legal guidelines to maintain the integrity and security of collected samples. Tampering with samples is considered unethical and illegal, with severe consequences for individuals found guilty of such actions. Protocols and safeguards are in place to prevent and detect tampering.

6. Why is specimen labeling important?

Specimen labeling is crucial to maintain traceability and prevent mix-ups. Proper labeling ensures that each specimen is accurately identified with essential information such as the patient's name, date of collection, and type of specimen. This minimizes errors and ensures reliable results in research and diagnostics.

7. Why are blood samples collected for testing?

Blood samples are collected for testing because blood provides a wealth of information about a person's health. These samples can help diagnose diseases, monitor treatment responses, assess organ function, and screen for various medical conditions, making blood testing an essential tool in healthcare.

8. What is the method of taking specimens?

The method of taking specimens varies depending on the type of specimen and the purpose of collection. Common methods include blood draws (venipuncture), urine collection, tissue biopsies, swabs for saliva or nasopharyngeal specimens, and surgical procedures for surgical sections or tissue samples. Each method follows specific protocols to ensure the safety and integrity of the collected specimens.



Biological specimens, whether blood, tissue, or other materials, are the bedrock of medical progress. 

So, the next time you encounter the term "biological specimen," remember the incredible impact these materials have on our lives. 

At Infiuss Health, we take pride in our role as custodians of this invaluable resource, facilitating its journey from Africa to laboratories across the globe. Learn more about us by sending a message to [email protected]

For more insights into biological research, stay tuned to our blog. 


Biospecimen research Biospecimens

Join our newsletter

Learn more about clinical data collection and research today.