Terminology in any field is a complex mix of established conventions,
accepted usages, disputed terms, and occasional misnomers. The termino
logy that has evolved for quantitative fluorescence cytometry (QFCM) i
s especially multifarious, in part because QFCM encompasses a range fr
om subjective visual assessments to objective photon counts. Thus, whi
le descriptive terms such as ''dim'' and ''bright'' are still quite us
eful, quantitative terms such as ''binding capacity'' should be used w
ith collective understanding of their exact meanings. This article rev
iews current usage and proposes definitions that, with refinement from
suppliers and users of QFCM technology, can provide the required clar
ity (C) 1998 Wiley-Liss,Inc.(dagger).