Mrs. Mitcheltree has worked as a laboratory technician since 1959 – first at the former Elk County General Hospital in Ridgway and later at what is now Elk Regional Health Center in St. Marys. Over the years, she has witnessed first-hand the evolution of pregnancy testing.
“Our hospital had six frogs, which was a major thing back then, and I remember thinking, ‘Why did I get myself into this?’” Mrs. Mitcheltree remembered with a laugh. “Back then, people didn’t wear exam gloves. Doctors did, but nurses and lab workers didn’t. I had to wrap towels around both my hands and put another towel around the frog so I didn’t have to touch it!”
The Hogben Test
In 1939, a British biologist named Lancelot Hogben discovered that injecting a female African Clawed Frog with serum from a pregnant woman would cause the frog to lay eggs. If the woman wasn’t pregnant, the serum would have no effect.
Dr. Hogben’s test proved to be a major breakthrough in pregnancy testing for two reasons: it was remarkably accurate and the test could be run repeatedly on an individual frog.
Until the mid-1960s, the Hogben Test was used at hospitals across the globe – including Elk County General Hospital.
Conducting The Test
“At about $70 each, the frogs were very expensive,” Mrs. Mitcheltree said. “That was a lot of money back then, so it was really something that we were able to have six of them. But my goodness, were they ugly.”
Mrs. Mitcheltree said a test tube full of blood would be taken from a woman who thought she was pregnant. The blood would be put into a special machine and spun at high speeds until a layer of clear fluid appeared at the top of the test tube. Lab workers would then draw that clear liquid and mix it with a special reagent.
“Then, it came time to get the frog,” Mrs. Mitcheltree said. “You’d pick up the frog and put it head-first into a special holder so that its rear-end was sticking up. Then you’d inject the serum into a lymph sac near its hind legs, take the frog out of the special holder, isolate it, and wait. If the woman was pregnant, the frog would lay eggs within 8 to 12 hours of being injected with the serum. It was amazingly accurate.”
Caring for the Frogs
Caring for the frogs was a job in and of itself, Mrs. Mitcheltree said.
“We kept the frogs in individual cages that sat in two big tubs of water in the ladies’ restroom,” she said with a laugh. “That sounds terrible now, but it was just this routine thing back then.
“We’d have to go to the market and buy a pound of liver, chop it up into small pieces and freeze it. Every day, you’d put a bit of liver on a stick and hold it down toward the frog. They’d come right up to get their pieces of liver. We had to put fresh water into their tubs every day. You didn’t dare let it run right into the tub, because it would hurt their eardrums. You had to let the water run over your hand and down into the tub.
“It used to be that only women worked in the laboratory. I have to say that the happiest day for all of us was when they finally hired a male laboratory technician. After that, we made him touch the frogs!”