All of the cell lines should express lck. lck trascription uses two
promoters, the proximal and the distal. The proximal is turned on in both
double negatives and double positives, and is turned off as the cells
enter the periphery. The distal is always on. The significance of this
regulation is not clear. There is significant literature of the use of
electroporation of the T cell lines you mention. Check Art Weiss' papers
for the Jurkat line and Ken Murphy for EL4. good luck
Andrey Shaw
