【求助】相对光单位

我在看文献的时候，不是十分明白用相对光单位/mg 蛋白表示转染效率，相对光单位的值多大才表示转染效率高（>50左右）呢？

把文献贴出来。

Figure 7. In vitro and In vivo gene delivery assay by using GE11 peptide as the targeting element. A) Transfection efficiencies of various PEI, ePEI, or gPEI polyplexes in SMMC-7721 cells at N/P ratios of 10:1. In the blocking assay, 0.5 mM free peptide GE11 was coincubated with the polyplexes. Results are shown as relative light units (RLU)/mg protein. One microgram plasmid DNA per well was used. B) In vivo gene delivery of DNA polyplexes. 50 µg pGL3 plasmid DNA was condensed with PEI, ePEI, or gPEI at N/P ratio (10:1). The DNA polyplexes were injected intravenously into SMMC-7721 tumor-bearing mice. Luciferase activities were measured after 24 h. In the competitive assay, 100 µg free peptide GE11 was coinjected with the gPEI/DNA polyplexes. Data are shown as mean ±SD (n=5).

在图片里有相对光单位

这个RLU（吸光度值/酶量或蛋白量）是相对值，大致相当于酶的活性，不能说高于多少效率就高。只能通过与对照组相比，统计学分析结果才说话转染效率是否有差异。

谢谢您！:)