- Staphylococcus aureus is known to produce coagulase, which can clot plama into gel in tube or agglutinate cocci in slide. This test is useful in differentiating S.aureus from other coagulase-negative staphylococci.
- Most strains of S.aureus produce two types of coagulase, free coagulase and bound coagulase. While free coagulase is an enzyme that is secreted extracellularly, bound coagulase is a cell wall associated protein. Free coagulase is detected in tube coagulase test and bound coagulase is detected in slide coagulase test.
- Slide coagulase test may be used to screen isolates of S.aureus and tube coagulase may be used for confirmation. While there are seven antigenic types of free coagulase, only one antigenic type of bound coagulase exists. Free coagulase is heat labile while bound coagulase is heat stable.
Coagulase Test
