ABSTRACT
Nonlinearity of destruction curves of bacterial spores has been attributed to the lack of homogeneity of the spore population (8); a similar principle may be at work here. Because of the variety of responses in development of inactivation curves, it has been difficult to apply standard FH calculations to depyrogenation studies, since an accurate z-value is necessary for these calculations (11). It has also been noted that D-value calculations rely on first-order kinetics throughout the entire process (12); the biphasic model for endotoxin inactivation would indicate that estimation of a D-value is not appropriate.
