I have been transformed my ligation product using vector pRGEB32 and insert gRNA into E.coli TOP 10, I just got a few colony, and after I did the mini-prep, it shows that at the same plate, some colony have difference size (bp). The "right" colony should have a size that almost the same with vector pRGEB32 at 15 kb, because I only add 24 nt for gene insert, but the other colony have difference size below 15kb. How this can be happened ?