What anticoagulant is commonly used for blood cultures in microbiology?

The most commonly used anticoagulant for blood cultures in microbiology is Sodium Polyanehole Sulfonate, or SPS. SPS is specifically formulated to inhibit the activity of the phagocytic cells and reduces the growth of certain bacterial contaminants without impairing the growth of most clinically relevant pathogens. This characteristic makes it particularly valuable in blood culture specimens, where the primary goal is to promote the growth of potential pathogens from a patient's bloodstream while minimizing the risk of contamination that could lead to false positive results.

Other anticoagulants, such as heparin or EDTA, can interfere with microbial growth or alter the characteristics of the blood culture, making them unsuitable for this purpose. For instance, heparin can cause clumping of cells and may inhibit certain bacteria from growing, while EDTA binds calcium, which is essential for some microbial enzyme systems. Citrate serves a similar role in binding calcium and is also not optimal for blood cultures. Therefore, SPS is the preferred choice in the context of microbiological blood cultures, ensuring accurate and effective pathogen detection.