Adding explicit serial number support is on our wishlist, but unfortunately it’s not yet available.

In the meantime, if you're not already using sublocations, you could try using them to keep track of the serial numbers. This isn't exactly what it's designed for, but it’s worked well for a number of people.

To turn on sublocations, make sure the option "Show Sublocation" is on under Company Settings --> Company --> Products & Inventory.

When you purchase/receive your products, you can type in the serial number into the Sublocation column. Then when you sell it, you can again pick it from that Sublocation column.  Then if you want to find what happened with that serial number, you can:

1.       View the History from the Inventory module.
2.       Click the “More” link to bring up the advanced search options.
3.       In “From Sublocation”, type in the serial number that you want to look up.
4.       Click Search.

From the History screen, you can also double click on the row to bring up any related orders. This'll let you quickly look up who that particular item was sold to.