Objective To develop an alternative method for assessment of gene delivery systems in vivo. Methods Mouse primary spleen lymphocytes were genetically modified in vitro by a retroviral vector harboring a Gaussia luciferase (Gluc) expression cassette. After implantation of these cells into recipient mice

the expression of Gluc was detected in whole blood or plasma collected. Results As little as 10 uL whole blood drawn from the recipient mice could guarantee prompt reading of Gluc activity with a luminometer. And the reading was found in good correlation with the number of genetically modified spleen lymphocytes implanted to the mice. Conclusions Gluc may be useful as an in vivo reporter for gene therapy researches

and Gluc blood assay could provide an alternative method for assessment of gene delivery systems in vivo.