Pulse shape analysis (PulSA) to track protein translocalization in cells by flow cytometry: applications for polyglutamine aggregation.

Pulse shape analysis (PulSA) is a flow cytometry-based method that can be used to study protein localization patterns in cells. Examples for its use include tracking the formation of inclusion bodies of polyglutamine-expanded proteins and other aggregating proteins. The method can also be used for phenomena relating to protein movements in cells such as translocation from the cytoplasm to the nucleus, trafficking from the plasma membrane to the Golgi, and stress granule formation. An attractive feature is its capacity to quantify these parameters in whole-cell populations very quickly and in high throughput. We describe the basic experimental details for performing PulSA using expression of GFP-tagged proteins, endogenous proteins labelled immunofluorescently, and organelle dyes.