SPS in blood collection stands for Sodium Polyanethole Sulfonate, and it's primarily used as an anticoagulant in blood culture collection bottles.
Here's a more detailed explanation:
- Anticoagulant Function: SPS prevents blood from clotting. This is crucial in blood cultures because clotting can trap bacteria and hinder their detection, leading to false-negative results.
- Antimicrobial Properties: Beyond its anticoagulant properties, SPS also exhibits some degree of antimicrobial activity. It can neutralize certain components in the blood that might inhibit bacterial growth. Specifically, it inactivates complement, which is a part of the immune system that can kill bacteria. It also inhibits the activity of phagocytes and some antibiotics.
- Blood Culture Bottles: SPS is most commonly found in blood culture bottles, often used to test for bloodstream infections (bacteremia or septicemia). The color of the bottle cap often indicates the type of culture media and the presence of SPS.
- Concentration: The concentration of SPS is carefully controlled to prevent it from inhibiting the growth of clinically relevant microorganisms.
- Mechanism of Action: The exact mechanism by which SPS acts as an anticoagulant is not fully understood, but it is believed to interfere with the activation of the clotting cascade.
In summary, SPS is a vital component in blood culture collection because it prevents clotting and neutralizes some antibacterial factors in the blood, promoting the accurate detection of microorganisms.
