I was visiting my 84 year old father in law, and he told me about a time when he and friends would go out and catch "platanna" frogs and sell them. "they were used to detect early pregnancy" he told me!
So I decided to do look into it and lo and behold, this is what I found.
After reading and digesting various writings on this "Hogben test" here it is in a nutshell.
While teaching in South Africa, British biologist - Lancelot Hogben found what he called a godsend for hormone research: the African Clawed Frog (Xenopus laevis) (aka Platanna in SA)
The Hogben test got it's start in 1930, when Lancelot Hogben discovered that these frogs were sensitive to hormone changes.
So after much research and cleverness, they discovered that, if after injecting a woman's urine into the back of the frog, the frog laid eggs 12 to 24 hours later, the woman was pregnant.
The frogs were the precursor to the "pee on a stick" test we have today.
Prior to the Hogben test, in the 20's and 30's, the best available test was a process called the A-Z test.
This was less accurate and a whole lot more gruesome.
It involved injecting female mice, rats or rabbits with a woman's urine, waiting a few days, killing the rodents and then examining the ovaries for any enlargement spurred by the hormone hCG (hGC is the hormone found in pregnant women) By 1935 an English lab was performing 6000 A-Z tests a year. Can you imagine how many animals has to be killed in that period?!
In 1937, Hogben and animal geneticist Francis Crew imported 1500 frogs to the UK from South Africa. Within 2 years they had worked out how to raise the frogs in labs (the biggest initial challenge) and make the Hogben test something easy for doctors to order.
The frogs were not killed in the process, and could in fact be used again and again. Also, frogs are obviously less expensive to raise and it took only one injection into one animal.
The A-Z test required two injections a day for three days in up to 5 rodents (all having to be sacrificed) and the test was not always 100% accurate as stated earlier, whereas the Hogben test was found to be almost 100% accurate.
The facility established by Hogben and Crew performed tens of thousands of these tests over more than two decades - until a simpler, animal - free, cell based test emerged in the 1960's, which hit the market in the 1970's.
GO SOUTH AFRICA GO!!!!!