Protein misfolding and subsequent aggregation through the self-assembly of misfolded proteins have now been established as the hallmark of numerous diseases. However, there are several facts yet to be explored. Some of these are:

• Aggregation is mostly studied in vitro at micromolar to millimolar concentrations, whereas aggregation of many proteins occurs at nanomolar levels at in vivo conditions. The Nature of aggregation at such a low concentration regime is not well explored.

• There is a limited experimental approach that probes the heterogeneity of the aggregation.

• The role of water in protein aggregation and associated toxicity is not known.

• The mechanism of amyloid toxicity is not yet understood.

The primary goal of my research is to gain insight into those unexplored facts. In my current work, we investigated the aggregation of stem Bromelain at physiological pH induced with 10% ethanol. Our results indicate that FCS, a Single molecular level technique is better in two ways: (i) it can probe aggregation of much smaller size at much lower protein concentration where the other bulk measurements like ThT-emission fail (ii) it captures the underlying heterogeneity in the process. Many things need to be done in the future including measurement of actual critical concentration and kinetic measurement.