The invention provides lentiviral preparations containing a sulfonic acid buffer, such as 1,4-piperazinediethanesulfonic acid (PIPES), 2-(N-morpholino)ethanesulfonic acid (MES), and 3-morpholinopropane-1-sulfonic acid (MOPS), a sodium citrate buffer, or a phosphate buffer. The invention additionally encompasses methods of lentiviral purification as well as methods of transducing human cells.