A

B

Figure 4. Optimisation experiments of Transfectam to DNA Ratio in transfected cells. Duplicate independent transfections were carried out using the carrier to DNA ratios indicated below. One set was analysed by slot blot hybridisation (A) using total DNA (4 m g DNA/slot), and the second set (B) by dot-blot hybridisation, using chromosomal-enriched DNA (1.0 m g DNA /blot) from the Hirt fraction described under Materials and Methods. In both cases, control lanes were: C⁺ = pCMVL DNA (10⁹ copies = 1 ng), and C ^- = CHSE-214 cell DNA (1.0 m g). Boxes 1 to 6 represent different Transfectam/DNA charge ratios expressed in m g, and R = the corresponding ratio. (Box 1) 2.5/5.0, R=0.5; (Box 2) 2.5/2.5, R=1.0; (Box 3) 2.5/1.0, R=2.5; (Box 4) 6.25 /1.0, R=6.25; (Box 5) 6.25/5.0, R=1.25; (Box 6) 12.5/10.0, R=1.25. The vector pCMVL DIG-labelled was used as probe.