Figure 1. Linearity of the telomeric repeat amplification protocol (TRAP) using reverse primer-linked probe in cancer cell line.

Cell extracts equivalent to the indicated numbers of A549 cells were tested for telomerase activity. Results in gel electrophoresis (left), amplification plot (above) and standard curves (below) consistently indicated the linear relationship between the telomerase activity and A549 cell number, while 5 represented a negative control.