Fig. 3.

Bioluminescence of MIP-Luc-VU islets correlates with the number of islets in vitro. Islets in quantities of 10, 25, 50, and 100 islets (left to right) were placed in a 24-well plate and in vitro bioluminescence imaging was performed after addition of luciferin (lower panel). Quantification of in vitro bioluminescence (left y-axis) reveals linear correlation between bioluminescence intensity and the number of islets (black squares; upper panel). Luciferase activity in islet lysates (right y-axis), as measured by luminometer, also correlates with the number of islets (open circles; upper panel).