Is it necessary to synchronize cells?

Exponentially growing cultured cells are growing at difference cell cycle stages, termed asynchronous.  Scientists are vigilant in their techniques to ensure they are using non-confluent cells prior to their experiments; thus, synchronization is not commonly employed.  However, synchronizing your cells can help improve the results of certain cell based assays such as viral integration or migration assays.  The most popular synchronization method is to serum starve cells for 12 to 24 hours, with chemical inhibitors being a viable alternative.