FIG. 2.

Characterization of simplified ADA retrovirus producer clones. (A) RNA dot blot analysis of serial dilutions of retroviral supernatant from each clone as a measure of relative titer (left). The graph depicts the dot intensity of each clone. (B) Titer estimation by Southern blot analysis of HeLa cells transduced with equal volumes of supernatant from each producer cell clone. Relative proviral copy number (ratio) is determined as the ratio of the phosphorimager signal of the viral ADA band (LASN, 3.12 kb; MLV and MPSV, 1.90 kb; SL3-3, 1.97 kb) to the intensity of the endogenous ADA band (2.61 kb).