E. coli didin't grow

E. coli that was integrated an Ampicillin resistance gene generated many colonies on LB agarose plates containing Ampicillin. I took the colonies and put them into LB liquid mediums containing Ampicillin. There is no reason that the bacteria that grow on LB agarose plate don't grow in the LB liquid medium, whereas they sometimes don't grow. Although it usually happens under ten percent degree, I couldn't see any growth of bacteria in LB liquid medium today. Because I might have mistaken the Ampicillin for an another antibiotic, I will try again, whereas I had never had such a mistake.