Blood sample collection from small laboratory animals is essential for various scientific research purposes. It is crucial to minimize stress and pain during the process to ensure accurate study outcomes. This article outlines approved blood collection techniques for rodents, lagomorphs, and nonrodents, emphasizing the importance of ethical approval from the Institute Animal Ethics Committee. General principles include using the least painful and stressful methods, ensuring adequate training for personnel, and considering the frequency and volume of blood collection. Blood is typically collected from venous, arterial, or heart chambers. For nonrodents, blood collection should not exceed 10% of the total blood volume in a single session, with a maximum of 0.6 ml/kg/day. Temporary cannulas can reduce pain and stress. Common methods include saphenous vein, dorsal pedal vein, tail vein, tail snip, orbital sinus, jugular vein, and temporary cannula. Each method has specific procedures, equipment, and precautions. For example, the saphenous vein method involves shaving the hind leg, applying local anesthetic, and using a 20G needle. The dorsal pedal vein requires cleaning the hind foot and puncturing the vein with a 23G/27G needle. Tail vein collection involves warming the animal and using a 23G needle, while orbital sinus collection uses general anesthesia and a capillary tube. Blood collection through temporary cannula involves cannulating the tail vein and using a 25G needle. Vessel cannulation allows for continuous sampling and requires surgical procedures. Cardiac puncture is used for terminal studies, and posterior vena cava collection involves abdominal surgery. Blood collection must be done under aseptic conditions, with careful monitoring to prevent complications. Proper labeling of blood collection tubes is essential. The article also highlights the importance of minimizing the number of attempts and ensuring the availability of necessary chemicals and equipment. The procedures are detailed for various species, with specific needle sizes and volumes recommended. Overall, the goal is to ensure humane and effective blood collection for scientific research.Blood sample collection from small laboratory animals is essential for various scientific research purposes. It is crucial to minimize stress and pain during the process to ensure accurate study outcomes. This article outlines approved blood collection techniques for rodents, lagomorphs, and nonrodents, emphasizing the importance of ethical approval from the Institute Animal Ethics Committee. General principles include using the least painful and stressful methods, ensuring adequate training for personnel, and considering the frequency and volume of blood collection. Blood is typically collected from venous, arterial, or heart chambers. For nonrodents, blood collection should not exceed 10% of the total blood volume in a single session, with a maximum of 0.6 ml/kg/day. Temporary cannulas can reduce pain and stress. Common methods include saphenous vein, dorsal pedal vein, tail vein, tail snip, orbital sinus, jugular vein, and temporary cannula. Each method has specific procedures, equipment, and precautions. For example, the saphenous vein method involves shaving the hind leg, applying local anesthetic, and using a 20G needle. The dorsal pedal vein requires cleaning the hind foot and puncturing the vein with a 23G/27G needle. Tail vein collection involves warming the animal and using a 23G needle, while orbital sinus collection uses general anesthesia and a capillary tube. Blood collection through temporary cannula involves cannulating the tail vein and using a 25G needle. Vessel cannulation allows for continuous sampling and requires surgical procedures. Cardiac puncture is used for terminal studies, and posterior vena cava collection involves abdominal surgery. Blood collection must be done under aseptic conditions, with careful monitoring to prevent complications. Proper labeling of blood collection tubes is essential. The article also highlights the importance of minimizing the number of attempts and ensuring the availability of necessary chemicals and equipment. The procedures are detailed for various species, with specific needle sizes and volumes recommended. Overall, the goal is to ensure humane and effective blood collection for scientific research.