Tracking the clustering dynamics in ternary particle mixtures by flow cytometry

Competitive heteroaggregation in a ternary mixture of polystyrene and melamine-formaldehyde particles was studied by multi-colour flow cytometric analyses. Flow cytometry is a very powerful technique for the determination of multi-dimensional cluster composition and its dynamic evolution. Three-dimensional cluster composition distributions were obtained that characterise the aggregation process separately for each species in a very detailed manner and pave the way for a higher dimensional analysis of cluster composition. The multi-species aggregation dynamics were analysed for systems with different mixing ratios of 1:1:1 and 1:20:1 as well as in dosage experiments. The results confirm the control of aggregation phenomena by the concentration ratios of constituent particle species, which might prove central for future tailoring of heteroaggregate compositions. Dosage experiments demonstrate the high sensitivity of flow cytometric measurements and their versatile technological applicability.