Answer: The two possible explanation for the outcome are as follows:
Step-by-step explanation:
1. The bacterial DNA in the pellet was not completely isolated properly, therefore, no fluorescence was observed in the pellet under the exposure of UV radiation.
2. After 3 hours of induction with the IPTG and labeling with the G3. The IPGT might not be able to bound to the bacterial DNA that could show response of fluorescence in the ultraviolet light.