Microsoft Co-pilot's answer and reference publication.

The comparison between Gaussia Luciferase (Gluc) and Firefly Luciferase (Fluc) for bioluminescence tumor monitoring reveals some interesting findings:

• Gluc is a secreted reporter, which means its expression in living animals can be assessed by in vivo bioluminescence imaging (BLI) or blood assays https://journals.sagepub.com/doi/pdf/10.2310/7290.2010.00057.

• In a study, mice were inoculated subcutaneously with tumor cells expressing both Fluc and Gluc. The researchers then performed Fluc BLI, Gluc BLI, blood assays of Gluc activity, and caliper measurement https://journals.sagepub.com/doi/pdf/10.2310/7290.2010.00057.

• The signal from the tumor in Gluc BLI peaked immediately and then decreased rapidly, which suggests that Gluc can be used for immediate but not long-term monitoring https://journals.sagepub.com/doi/pdf/10.2310/7290.2010.00057.

• All measures indicated an increase in tumor burden early after cell inoculation. However, the increase reached plateaus in both Gluc BLI and Fluc BLI despite a continuous increase in the caliper measurement and Gluc blood assay https://journals.sagepub.com/doi/pdf/10.2310/7290.2010.00057.

• There were significant correlations found between the measures, and the correlation between the blood signal and caliper volume was especially high https://journals.sagepub.com/doi/pdf/10.2310/7290.2010.00057.

• The study concluded that Gluc allows tumor monitoring in mice and should be applicable to dual-reporter assessment in combination with Fluc. The Gluc blood assay appears to provide a reliable indicator of viable tumor burden https://journals.sagepub.com/doi/pdf/10.2310/7290.2010.00057.

The combination of a blood assay and in vivo BLI using Gluc should be promising for quantifying and localizing tumors. It's important to note that while Gluc offers certain advantages, such as the ability to monitor tumors via blood assays, Fluc is still widely used due to its lower background signal and versatility in applications, especially for long-term monitoring https://journals.sagepub.com/doi/pdf/10.2310/7290.2010.00057.

Inoue, Yusuke, et al. "Gaussia luciferase for bioluminescence tumor monitoring in comparison with firefly luciferase." Molecular imaging 10.5 (2011): 7290-2010. Article Gaussia Luciferase for Bioluminescence Tumor Monitoring in C...