For STG125, Britons can now purchase a home DNA kit to get information about their health, ancestry and family traits.

A personal DNA testing kit that gives users an insight into their genetic make up has gone on sale in the UK.

The 23andMe Personal Genome Service (PGS) costs STG125 ($A228) and claims to offer access to more than 100 pieces of information about a person's health, ancestry and family traits.

Users spit in a tube, seal it and send it off to be analysed in a laboratory.

After four to six weeks they can log in online to see a detailed report of their results.

The kit, which has been part-funded by Google, said the tool is not "diagnostic" but includes results of tests for genes associated with inherited conditions such as cystic fibrosis or sickle cell anaemia.

It also tests for genes that may reveal risk factors for diseases or conditions such as blood clotting, Alzheimer's or Parkinson's.

In addition to findings about their health, the firm says users can explore the genetics behind why they may be a more frequent smoker, how they metabolise caffeine and their body's response to diet and exercise.

They can see information about the genetic basis of traits such as hair colour, freckling, height and hair loss.

The service also includes a "full genetic ancestry report" allowing people to trace their family's genetic roots and "potentially discover and communicate with new relatives", according to 23andMe.

The firm says on its website that it is "committed to maintaining the security and confidentiality of your personal information" and has put in place security measures to help protect against the "loss, misuse or alteration of information under our control".

About 10,000 UK-based customers have already paid extra to have the kit delivered from the US.

AAP.