- 14 C Phe Incorporated Counts Min 4 5 4 3 5 3 2 5 2 1 5 1 0 5 0 0 20 Control Poly U Poly U Ricin 10 30 Figure 2 Eff 1 (145.69 KiB) Viewed 28 times
Why is the background level of incorporation not zero?
What conclusion can be drawn from this experiment?
[14-C] Phe incorporated (counts/min 4.5 4 3.5 3 2.5 2 1.5 1 0.5 0 0 20 control poly-U poly-U + ricin 10 30 Figure 2. Effect of ricin on polyphenylalanine synthesis. A cell free system was preincubated at 28° for 40 minutes in the absence of labelled compounds. Then 4 µCi of ¹4C phenylalanine was added, and the system was divided into three equal samples. One sample (▲) was used as a control, another sample (●) contained 100 µg of poly-U and a third sample (X) contained 100 µg of poly-U and 0.5 µg of ricin. The samples were incubated at 28°C and aliquots were removed as indicated, and the acid-precipitatable radioactivity was determined. Source: Redrawn from Figure 2 of Olsnes and Phl, 1972.