Cultures glowing under UV light annotate transformation of the original bacteria with the pGLO plasmid. Bacteria without the pGLO plasmid will neither glow under UV light nor be ampicillin resistant. If this is true, how can we have healthy, non-glowing, non-ampicillin resistant E. coli colonies growing on the LB/Amp/Ara plate

Contamination

Explanation: This is a known contrainst when performing transformation in the lab. Normally the Pglo plasmid asides glowing under UV, possess a Amp gene that codes for resistance to the antibiotics Ampicillin. Transform cells will survive while untransformed cells will normally die. If untransformed (non glowing, non Ampicillin resistant) cells thrive in the medium, it is definitely a case of contamination. Start again but this time, disinfect appropriately bad be cautious of any potential contamination.