Want to know whether you are an early bird or a night owl? There is no need to go for blood examination, for researchers have developed a simple genetic test which can identify your sleep pattern.

Earlier, blood samples were required to obtain the ribonucleic acid needed to determine a person's natural pattern of wake and sleep -- known as the circadian rhythm. Now, all that you need is a simple mouth swab.

"Our technique allows us to get a usable sample just by swabbing the inside of an individual's cheek," the British media quoted Sarah Forbes-Robertson, who led the team at the University of Swansea, as saying.

A number of different genes control an individual's natural circadian rhythm. The levels of RNA produced by these different genes indicate how active they are at different times of day. One gene known as Per2 produces the highest levels of RNA at around 4 AM, and is the gene associated with sleep, the researchers said.Another gene which produces the highest levels of RNA at 4 PM, known as REV-ERB, works in opposition to Per2 and is thought to be associated with wakefulness, according to the Swansea team.