By . Damien Gayle . This is the moment that Cai Juanjuan thought would never happen - the chance to hold her missing daughter in her arms again more than two decades after she went missing. Cai Ruru was only four years old when she was snatched from her grandmother's home in the city of Ruian in Zhejian province, east China. Mrs Cai feared she would never see her . daughter again. But thanks to a nationwide DNA database set up to try . to trace the background of lost children, the pair have been reunited. Poignant: The moment Cai Ruru is reunited with her mother Cai Juanjuan, two decades after she was snatched from her grandmother's home and taken hundreds of miles away to be sold into adoption . Moving: Mrs Cai had feared that she would never see her daughter again, but they have been reunited thanks to a nationwide DNA database set up five years ago to trace lost children in China . Ruru embraces her mother: She was one of the tens of thousands of children kidnapped every year in China . It comes after 25 years of heartache. On the day Ruru was taken, Mrs Cai and her husband, Li Mianquan, had left her with her grandmother while they went out to work. 'My mother-in-law knew that our daughter was well-behaved, so she hadn't bothered to lock the door when she went shopping,' said Mrs Cai. 'When she came back 30 minutes later the house was empty and daughter had vanished.' Despite scouring the area for weeks and filing reports with the authorities they were unable to find Ruru. Ruru in an old photo: Kidnappers struck while Ruru was at her grandmother's house, where her mother and father had left her while they were at work . The grandmother died broken-hearted four years ago, but Mrs Cai and her husband refused to give up hope. They were some of the first to leave samples with DNA database when it was set up in 2009, but for years they heard nothing. China suffers from an epidemic of . child kidnapping, with tens of thousands abducted every year for sale . into adoption, forced labour and prostitution. But Ruru had been lucky. Rather than face the sad fate of many of China's snatched children she had ended up with a good family in Putian, a city in Fujian province, who believed they were adopting an abandoned child. Ruru's adoptive parents had paid money . for her, but they believed the cash was to grease the wheels of China's . notorious bureaucracy and speed up the adoption process. They . gave the girl the surname Wong, and when she was eight her parents told . her that she was adopted. This year she finally decided to search for . her real parents and she, too, gave a sample to the database. Ruru, . now 29, said: 'My adoptive parents had two sons but no daughter, so . they had arranged to adopt me. I was the oldest child in the family. 'I . have to say they treated me very well, I don't have any complaints, but . I wanted to find out who my real parents were. I wanted to tell them I . was okay and didn't want them to have any regrets.' Mrs Cai and her daughter as a toddler: The grandmother died broken-hearted four years ago, but Mrs Cai and her husband were some of the first to leave samples with DNA database when it was set up in 2009 . 'I was determined not to cry, but when I saw the beautiful young woman my daughter has become I couldn't help it,' said Mrs Cai after she was reunited with Ruru at Bao'an Airport in the city of Shenzhen . Estimates of the number of kidnapped children in China range from 10,000 per year to as high as 70,000. Most parents who lose children stand very little chance of getting them back. Mrs Cai believed that she was also destined to never see her daughter again. But then she got the call from police to say that they had a match for her DNA - her daughter had been found. She said: 'I couldn't believe it, I was almost too scared to believe it. But then I bought a ticket straight away and flew to meet her.' And as a result the child, now a young woman with a husband and child of her own, met her real mother at Bao'an Airport in the city of Shenzhen. Her mother said: 'I was determined not to cry, but when I saw the beautiful young woman my daughter has become I couldn't help it.'
Tens of thousands of children are kidnapped for sale every year in China .
They are sold into adoption, forced labour and, in some cases, prostitution .
Cai Ruru and her mother Cai Juanjuan were reunited thanks to DNA match .
China operates huge DNA database to trace the background of lost children .
By . Damien Gayle . This is the moment that Cai Juanjuan thought would never happen - the chance to hold her missing daughter in her arms again more than two decades after she went missing. Cai Ruru was only four years old when she was snatched from her grandmother's home in the city of Ruian in Zhejian province, east China. Mrs Cai feared she would never see her . daughter again. But thanks to a nationwide DNA database set up to try . to trace the background of lost children, the pair have been reunited. Poignant: The moment Cai Ruru is reunited with her mother Cai Juanjuan, two decades after she was snatched from her grandmother's home and taken hundreds of miles away to be sold into adoption . Moving: Mrs Cai had feared that she would never see her daughter again, but they have been reunited thanks to a nationwide DNA database set up five years ago to trace lost children in China . Ruru embraces her mother: She was one of the tens of thousands of children kidnapped every year in China . It comes after 25 years of heartache. On the day Ruru was taken, Mrs Cai and her husband, Li Mianquan, had left her with her grandmother while they went out to work. 'My mother-in-law knew that our daughter was well-behaved, so she hadn't bothered to lock the door when she went shopping,' said Mrs Cai. 'When she came back 30 minutes later the house was empty and daughter had vanished.' Despite scouring the area for weeks and filing reports with the authorities they were unable to find Ruru. Ruru in an old photo: Kidnappers struck while Ruru was at her grandmother's house, where her mother and father had left her while they were at work . The grandmother died broken-hearted four years ago, but Mrs Cai and her husband refused to give up hope. They were some of the first to leave samples with DNA database when it was set up in 2009, but for years they heard nothing. China suffers from an epidemic of . child kidnapping, with tens of thousands abducted every year for sale . into adoption, forced labour and prostitution. But Ruru had been lucky. Rather than face the sad fate of many of China's snatched children she had ended up with a good family in Putian, a city in Fujian province, who believed they were adopting an abandoned child. Ruru's adoptive parents had paid money . for her, but they believed the cash was to grease the wheels of China's . notorious bureaucracy and speed up the adoption process. They . gave the girl the surname Wong, and when she was eight her parents told . her that she was adopted. This year she finally decided to search for . her real parents and she, too, gave a sample to the database. Ruru, . now 29, said: 'My adoptive parents had two sons but no daughter, so . they had arranged to adopt me. I was the oldest child in the family. 'I . have to say they treated me very well, I don't have any complaints, but . I wanted to find out who my real parents were. I wanted to tell them I . was okay and didn't want them to have any regrets.' Mrs Cai and her daughter as a toddler: The grandmother died broken-hearted four years ago, but Mrs Cai and her husband were some of the first to leave samples with DNA database when it was set up in 2009 . 'I was determined not to cry, but when I saw the beautiful young woman my daughter has become I couldn't help it,' said Mrs Cai after she was reunited with Ruru at Bao'an Airport in the city of Shenzhen . Estimates of the number of kidnapped children in China range from 10,000 per year to as high as 70,000. Most parents who lose children stand very little chance of getting them back. Mrs Cai believed that she was also destined to never see her daughter again. But then she got the call from police to say that they had a match for her DNA - her daughter had been found. She said: 'I couldn't believe it, I was almost too scared to believe it. But then I bought a ticket straight away and flew to meet her.' And as a result the child, now a young woman with a husband and child of her own, met her real mother at Bao'an Airport in the city of Shenzhen. Her mother said: 'I was determined not to cry, but when I saw the beautiful young woman my daughter has become I couldn't help it.'
try . to trace the background of lost children, Cai Ruru is reunited with her mother Cai thanks to a nationwide DNA database set up five thousands of children kidnapped every year in sale . into adoption, forced labour and