Walking around the streets of Manhattan recently, my curiosity was raised by an unusual advertisement on the roof of a yellow taxi cab. Simply written in bold pink against a black background, the text read "Who's the father?" with a toll-free phone number 1-800DNA-TYPE beside a thumb print.
It turns out that this is the nationwide billboard campaign for a company called Identigene in Houston, Texas. Its business is to determine children's paternity by conducting DNA tests. The company, which was founded in 1994, receives an average of 400 calls a day and solves 200 cases a week.
DNA identifies a person's genetic code and can come from a drop of blood, saliva, semen, mucus, skin cells, a strand of hair or even dandruff. Samples can then be compared to see if there is a match.
Ms Caroline Caskey, president and founder of Identigene, says her company can conduct a fast and accurate DNA test because it uses a new type of technology.
Her family background is in genetics and Identigene uses technology her father discovered in 1991 while working at the pharmaceutical giant Merck. Instead of using a blood sample, Ms Caskey said her company uses a technique called STR which stands for Short Tandem Repeat technology.
A swab is taken from cheek cells inside the mouth of the mother, alleged father and child. The cost for taking and analysing swabs from the trio is $475 (€456.77).
Identigene, Ms Caskey believes, has developed a niche in the private market, conducting tests for people who want peace of mind, rights for child support, divorce, or custody of their children.
The privately held company has seen "excellent growth" of about 100 per cent a year, says Ms Caskey. "With DNA typing, no one can do it the way we do it and none are nearly as fast as we are," she adds.
Results can be back in five to six days compared to the older process which took three to four weeks. For research and development purposes, she says, Identigene has converted to a fluorescent system for easier and faster detection of DNA. The company employs 30, mainly telephone staff.
Identigene works with hundreds of laboratories in the US and with five clinics overseas in the Czech Republic, Brazil, Korea, Mexico and Japan. Swabs are taken there and taken to Houston. The company is also looking to expand in Europe.
It recently launched a programme called Baby DNA ID at a hospital in Houston and next month will expand it to the largest cities in the US. In this, a DNA sample is taken from the mother and baby after birth and then once they return home after their hospital stay, the two are compared to confirm they match. "This gives the mother reassurance and peace of mind," Ms Caskey says. The baby's DNA sample is stored for five years and can be protected for life for an additional fee.
"It makes sense to take DNA, provided rules are in place on how to use or not to use it," Ms Caskey adds. In fact, the US government will pay for women on welfare to take a paternity test on their children so women can get child support payments from the biological fathers rather than from the government. A court order can be obtained to force a reluctant alleged father to provide a DNA sample. The departments of law enforcement are serious proponents of DNA testing and as such, it has become common police practice.
Ten years ago, the US's first DNA databank opened in the state of Virginia. There, DNA was first taken from convicted sex offenders. Then it expanded to burglars and now it is taken from all convicted felons.
Each of the 50 states in America all voted to build DNA databanks and 12 states have linked their computers together so samples can be compared by numeric code. Florida and 30 other states take DNA samples from people convicted of certain violent crimes. Another 10 states take DNA from everyone with a criminal conviction.
In New York City, detectives are being instructed to pick up items like chewing gum and tissues thrown away by suspects they are trailing. Under new DNA analysis, a process that previously cost $5,000 and took 16 weeks, can now be performed for about $80 and take as little as 72 hours.
When analysis is done, the findings can be conclusive and often result in either the exoneration or conviction of suspects.
One intriguing finding concerned the third president of the US, Thomas Jefferson, who was the author of the Declaration of Independence. Genetic testing conducted last year revealed that he had fathered a child by Sally Hemings, one of the African-American slaves he owned at his Monticello plantation in Virginia in the 18th century.
Last month, as part of the Jefferson family's 86th reunion, his descendants, a group known as the Monticello Association, invited Hemings's descendants for the first time. About 35 from that family came and the association agreed to consider membership applications from a descendant of each of the three male children that Hemings's relatives contend she had with Jefferson.
So, it seems even American history has been rewritten due to DNA testing.