The invention provides a method using a hemocyte preparation, for example,
Limulus amebocyte lysate, for detecting in a single assay the presence of
at least one of a Gram negative bacterium, a Gram positive bacterium, and
a fungus in a sample of interest. The method exploits the differential
reactivity of Gram negative bacteria, Gram positive bacteria, and fungi
with the hemocyte preparation to produce measurable changes in a
property, for example, an optical property, of the mixture. Because the
Gram negative bacteria, Gram positive bacteria and fungi each produce
different changes in a given property, for example, an optical property,
it is possible to classify the type of microorganism present in the
sample of interest.