Ohuruogu reached the 400m semi-finals in Athens four years ago
Britain's world 400m champion Christine Ohuruogu says she is ready to stake her claim for an Olympic gold medal after hitting form in the 400m.
The 24-year-old, who produced a major shock to claim the world title in 2007, ran a season's best of 50.99 seconds at a meeting in Lucerne on Wednesday.
"I think I am quite prepared for Beijing now," Ohuruogu said.
"I want to do the best I can and enjoy the Games. Before the Games I'll run a final 400m at Crystal Palace."
Ohuruogu will take part in a final competitive 400m at the London Grand Prix, staged over the weekend of 25 and 26 July, before making her final preparations for the Olympic 400m which starts on 16 August.
The Londoner has limited her 400m races this season, preferring instead to test her pace over 200m.
But Ohuruogu, who won her first major title at the Commonwealth Games in 2006, is confident she - and her British team-mates - are hitting peak form at the right time.
"This year I ran a lot of 200m races and I think this improved my speed a lot for the 400m," she added.
"Great Britain has a very good 4x400m relay team. We can win a medal."
Ohuruogu will be up against American number one Sanya Richards, compatriot Nicola Sanders, the world silver medallist, as well as a strong contingent of Russian and Jamaican runners.
Meanwhile, Harry Aikines-Aryeetey was just outside his personal best in the 100m at the meeting in Switzerland.
The 19-year-old, who goes to Beijing as part of Britain's 4x100m relay squad, finished behind American Mark Jelks in 10.22 seconds.
Live coverage of the Aviva London Grand Prix will feature on BBC TV and BBC Sport Interactive on 25 and 26 July.