User:
Rachel Friedman, a postdoc in the lab of Matthew Krummel, Associate Professor of Pathology at University of California, San Francisco
Project:
Investigating T cell-receptor dynamics during initial response to antigens
Problem:
Friedman images surgically exposed or explanted lymph nodes to examine T cell behavior. The inflammatory response draws nonspecific macrophages and dendritic cells to the lymph node; these emit their own autofluorescent light as bright as the light from the green fluorescent protein (GFP) marker she uses.
Solution:
Friedman compensates for background using dual labels. She injects a recipient mouse with T cells engineered to express a GFP-tagged antigen receptor activated by chicken ovalbumin. Since the green light from the GFP is almost identical to the surrounding autofluorescence, Friedman adds another label called Cell Tracker Orange. This "vital dye" permeates the membrane of living cells, binds to a protein only expressed in the transgenic T cells, and is easily ...
