pUC vector with small insert may give light blue colonies instead of white ones.
If you are using 5 ml overnight culture with the Miniprep kit, you can increase the overnight culture to 10 ml. But you have to double the volumes of Buffer P1, P2 and N3 during cell lysis. After clearing the lysate, then apply the entire supernatant to the spin column (since the lysate is more than 700 ul, you need to load the column twice). After washing with Buffer PE, elute DNA with 50 ul of Buffer EB.
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