Table 1. Fraction of APh labeled filaments that were observed to also be labeled with Rh-rIgG or fluorescent secondary antibody to monoclonal CD45 antibody.

Experiment	Fraction labeled(mean ± SEM)	Filament Formation Method	Comment
1	16±2%(n = 990)	1	Incubation in solution (100 nM Rh-rIgG). Observation in a60 assay solution
2	35±3% (n = 440)	1	Incubation in flow cell (10 nM Rh-rIgG), a60
3	16±2%(n = 503)	1	Incubation in solution (100 nM Rh-anti-mouse IgG). Observation in a60 assay solution. Monoclonal antibodies (CD45)
4	35±2%(n = 1196)	2	Incubation in solution (1000 nM Rh-rIgG), aMC130
5	49±4%(n = 382)	2	Incubation in solution(100 nM Rh-rIgG), aMC130

Data are given as mean ± SEM where SEM was estimated from the observed fraction, f, according to SEM = √f(1-f)/n where n was the total number of observed filaments in a given experiment. The data were obtained in assay solution as filament motility made it more straightforward to unequivocally associate all fluorescent molecules with filaments. Polyclonal antibodies (a-rIgG) were used if not otherwise stated.