Individual activities measured under simultaneous expression. (A) Every combination and the 10 single shRNA plasmids were separately transfected with each matched fluorescent reporter corresponding to its component shRNAs to measure the individual suppressive activities of each shRNA when expressed simultaneously with others. Activities are plotted according to total cassette number and each cassette position (1 to 7) (B). Different combinations of identical cassette number are grouped in columns (e.g. the 6 combinations of 5 cassettes), shRNA # is indicated by color coding, and the combination number for individual points is indicated where points differed from the main cluster. The combination numbers present in each column are given, and also color coded to match the shRNA in the position being tested and the matched reporter used (C). For example, combinations 6.2 (184.108.40.206.0.5), 6.8 (220.127.116.11.0.6) and 6.9 (18.104.22.168.9.5) in position 2 were assayed with the Pol-2670 reporter (matched to shRNA #4), and combinations 6.3 (22.214.171.124.7.6) - 6.7 (126.96.36.199.1.7) were assayed with the Vpu reporter (matched to shRNA #8). Values shown are representative of 3 independently repeated experiments.