0620813<br/>Simon<br/>The work in this proposal will optimize fluorophores for following single proteins in cells. This<br/>could significantly enhance the ability to study the roles of proteins in many different cellular<br/>reactions. There are some organic fluorophores that can be monovalently linked to proteins.<br/>Unfortunately, they are not photostable enough to be used for many biological studies. Quantum<br/>dots have significantly greater brightness and photostability. However, they aggregate and are<br/>multivalent in their linkages. This project will optimize the imaging techniques and designs of<br/>quantum dots to reduce aggregation and ensure that their linkages to proteins are monovalent.