Blood Sample Processing Techniques in Animals
Introduction:
Blood samples play a crucial role in diagnosing and monitoring the health of animals. Veterinary professionals rely on accurate and efficient blood sample processing techniques to obtain reliable results and provide appropriate medical care. This article will discuss various blood sample processing techniques commonly used in animals.
1. Venipuncture:
Venipuncture is the most common technique used to collect blood samples from animals. It involves inserting a needle into a vein, usually in the forearm or jugular vein, to obtain a sample. In larger animals, venipuncture is often performed under sedation or anesthesia.
2. Capillary Blood Collection:
Capillary blood collection is suitable for smaller animals, such as birds, reptiles, and small mammals. It involves pricking the skin and collecting blood from the capillaries using a microhematocrit tube or a capillary tube.
3. Plasma Separation:
To obtain plasma, the liquid portion of blood, the collected blood sample is usually placed in an anticoagulant tube, such as EDTA (ethylenediaminetetraacetic acid), and then centrifuged to separate the plasma from the cellular components.
4. Serum Separation:
Serum, the clear liquid portion of blood without any clotting factors, is obtained by allowing the blood sample to clot naturally. After clot formation, the sample is centrifuged to separate the serum from the clot.
5. Buffy Coat Preparation:
In some cases, when analysis of blood cells is necessary, a buffy coat preparation is performed. After centrifuging, the buffy coat, which contains mostly white blood cells and platelets, is carefully collected and used for specific tests.
6. Aliquoting:
After separating plasma or serum, the samples are divided into smaller volumes known as aliquots. Aliquoting allows for multiple tests to be performed on a single sample, minimizing the need for unnecessary blood drawing.
7. Cold Chain Storage:
To preserve the stability and integrity of certain blood components, such as hormones or enzymes, blood samples may need to be stored at specific temperatures during transportation and storage. Cold chain storage ensures that the sample remains viable for analysis.
8. Freezing and Thawing:
When long-term storage is required, blood samples are often frozen at -20°C or -80°C, depending on the stability of the analytes of interest. Freezing and thawing should be minimized to maintain the quality of the sample.
9. Proper Labeling and Documentation:
Accurate labeling and documentation are essential to prevent mix-ups or errors during processing. Each sample should be labeled with the animal’s identification, date, and any other relevant information. Additionally, maintaining detailed records is crucial for future reference.
10. Quality Control Measures:
Implementing quality control measures throughout the blood sample processing workflow is crucial to ensure accuracy and reliability of results. Regularly calibrating equipment, properly maintaining the centrifuge, and following standardized protocols are important steps in maintaining quality control.
11. Coping with Blood Hemolysis:
Hemolysis, or the breakdown of red blood cells, can occur during sample collection or processing. Hemolyzed samples can affect test results, particularly for certain analytes. Techniques should be implemented to minimize hemolysis, such as gentle mixing, careful handling, and prompt separation of cellular components from plasma or serum.
12. Microsampling Techniques:
In some cases, obtaining a large blood sample may not be feasible or ethical. Microsampling techniques involve collecting smaller volumes of blood using specialized devices. These techniques are particularly beneficial in studies involving laboratory animals or small-bodied wildlife.
13. Alternative Sample Types:
Besides traditional blood samples, other sample types can provide valuable diagnostic information. Saliva, tears, or even feces can contain biomarkers that are used for specific tests, reducing the need for blood collection in some cases.
14. Coagulation Profile Testing:
For animals requiring coagulation profile tests, additional processing steps are needed. Special anticoagulants, such as citrate or oxalate, are used to stabilize blood samples without forming clots before analysis.
15. Advanced Laboratory Techniques:
With advancements in technology, laboratory techniques are continuously evolving. Techniques such as polymerase chain reaction (PCR), flow cytometry, and immunoassays allow for detailed analysis of specific components within the blood samples.
16. Sterile Collection for Blood Cultures:
When collecting blood for culture to identify bacterial or fungal infections, sterile techniques must be followed. Aseptic collection methods and utilizing specialized culture media are crucial in obtaining reliable results.
17. Cytological Preparations:
In cases where evaluation of blood cell morphology is necessary, cytological preparations are performed. Smears are prepared by spreading a small amount of blood on a microscope slide, followed by staining, fixing, and examining under a microscope.
18. Point-of-Care Testing:
In certain situations, quick and immediate results are necessary, especially in emergencies. Point-of-care testing allows for rapid analysis of blood samples using handheld devices, providing instant information to guide treatment decisions.
19. Hematology Analyzers:
Hematology analyzers provide automated blood cell counting, differentiating between various types of white blood cells, red blood cells, and platelets. These devices save time and ensure accurate results with minimal manual intervention.
20. Continuous Education and Training:
Blood sample processing techniques continue to evolve, and veterinary professionals should engage in continuous education and training to stay updated with the latest advancements. This ensures the highest standard of care for animals and accurate interpretation of test results.
Questions and Answers:
1. What is the most common technique used to collect blood samples from animals?
– Venipuncture.
2. Which animals are suitable for capillary blood collection?
– Smaller animals like birds, reptiles, and small mammals.
3. How is plasma obtained from a blood sample?
– By placing the sample in an anticoagulant tube and centrifuging it.
4. What is serum separation?
– Allowing the blood sample to clot naturally and then separating the clear liquid (serum) from the clot.
5. What does the buffy coat contain?
– White blood cells and platelets.
6. What is the purpose of aliquoting?
– To divide the plasma or serum sample into smaller volumes for multiple tests.
7. Why is cold chain storage necessary for some blood samples?
– To preserve the stability of certain blood components during transportation and storage.
8. What is the recommended temperature for long-term storage of blood samples?
– -20°C or -80°C, depending on analyte stability.
9. Why is proper labeling and documentation important in blood sample processing?
– To prevent mix-ups or errors and maintain detailed records for future reference.
10. What are some quality control measures in blood sample processing?
– Regular calibration of equipment, maintaining the centrifuge, and following standardized protocols.
11. How can hemolysis be minimized during sample processing?
– Gentle mixing, careful handling, and prompt separation of cellular components.
12. What are microsampling techniques used for?
– Collecting smaller volumes of blood from laboratory animals or small-bodied wildlife.
13. Can biomarkers be found in alternative sample types?
– Yes, biomarkers can be identified in saliva, tears, or feces for certain tests.
14. When is coagulation profile testing necessary?
– For animals requiring evaluation of their coagulation system, special anticoagulants are used.
15. Name three advanced laboratory techniques used in blood sample analysis.
– Polymerase chain reaction (PCR), flow cytometry, and immunoassays.
16. What should be followed when collecting blood for culture testing?
– Sterile techniques, aseptic collection methods, and specialized culture media.
17. How are cytological preparations performed?
– By spreading a small amount of blood on a microscope slide, staining, fixing, and examining under a microscope.
18. What is the purpose of point-of-care testing?
– To provide rapid analysis and immediate results, especially in emergency situations.
19. What do hematology analyzers provide?
– Automated blood cell counting and differentiation between different blood cell types.
20. How can veterinary professionals stay updated with the latest blood sample processing techniques?
– Engaging in continuous education and training programs.
