First semester of college, I was a biochemistry major. I wanted to study neuroscience and find a cure for Alzheimer’s, so midway through the semester I thought I should sign up for a work study program working in a real lab to better my resume. So I attended a Job Fair at the Student Union in mid-fall and met a man named Ron
Hrstka who told me about his lab at the Gene Targeting Core Facility (
GTCF). The
GTCF “provides technical and research services to investigators on the University of Iowa campus and elsewhere for the generation of gene knockout mouse models,” Ron told me. “
Hmm…Lab Assistant at the Gene Targeting Core Facility, wow, that would look great on my resume,” I thought, so I went ahead and signed up that night.
I got a call from Ron the next day, and I started the following week at five thirty in the morning. Ron told me that I
wouldn’t be working in a normal lab, with beakers and test tubes, per
se, but rather in the ‘mouse colony,’ which housed over ten thousand mice. Since I had a copper-hooded pet rat named Copernicus as a teenager, I thought working with mice would be a similar pleasure. I would be responsible for feeding, or ‘grueling’ the mice in the morning, and then once the mice were fed, I would help Ron’s assistant in the mouse colony enter data about the mouse litters into a computer.
For starters, mice are separated into cages according to litter and marked soon after they are weaned. A hole punch is used to gouge a small semi-circular hole in the ear of the mouse according to their assigned number. No punch is number one. Upper right ear, number two. Lower right, three. Upper left, four. And finally, lower left five. If the litter is exceptionally large, a combination of ear-punches and toe-clipping is used. Toe-clipping involves completely removing one of the fingers of the mouse’s paw, and in this way a large number of mice can be accounted for. This was necessary since the particular lab I worked in housed approximately ten thousand mice, separated into cages of five. A labyrinthine system of hallways connected each room.
Before you entered a room in the mouse colony, you had to first enter a small 10x10 foot room in which you washed your hands up to the elbows, donned an aqua-blue surgical mask, hairnet, apron, surgical gloves and booties. I felt like a real neurosurgeon scrubbing up getting ready to enter the ER. Before you touched the doorknob to open the door, you had to use the spray bottle of alcohol on your gloved hands, and before you could step into the room you had to spray the bottom of your booties. Inside each room housed the mice, five or six rows of cages with five or six levels each, and an examination table, or ‘hood’ where the cages were brought to feed and examine the mice. The hood was about waist-level, and was encased in
Plexiglas and had a vent over it suck out the possibly contaminated air, and had another
Plexiglas door at the front. I was told in the unlikely event that any mice escaped from the hood while being examined, I was required to stomp on them so they
couldn't get out and contaminate the other mice. This would be difficult for a fugitive mouse to do, since the door of the hood was six inches higher than the floor, and the lowest level of cages was two feet off the ground. Also, a five millimeter gap separated the door from the floor, so escape into the other labyrinthine labs was nearly impossible.
The mice came in two colors: white and black. If the gene knockout was successful, the mouse was white with black spots. If it
wasn’t the mouse was all black. Black mice were of no use to the researchers and were killed. My job on Fridays was to dispose of the mice. The workers who cleaned the cages in the mornings before I arrived would separate the black mice and put them in a cage in the main office of the lab. Wearing the usual clothes I wore to class, sans surgical gear, I covered the cage with an aqua-blue surgical apron and walked a couple blocks to the medical lab that housed the gas chamber. Since the mice were going to be killed anyway, it
didn’t matter that they might get contaminated by their first venture into the outside world; the cage was covered so not to upset the other students in the Med Labs. The gas chamber was a small lab that resembled a doctor’s office, outfitted with several large tanks of CO2, similar to the helium tanks used to inflate balloons for a child’s party. Next came the hardest part of the job. I had to dump the mice in the cage—the black mice who were no use to the lab, along with breeder mice that had gotten too old to reproduce—into a white five-gallon bucket lined with a blue plastic bag marked “Hazardous Materials.” A lid with a two-inch hole in the center was firmly placed on top, and a hose running from the carbon dioxide tank was placed securely in the hole.
Once I was sure the seal was airtight, I turned the nozzle of the tank and counted to thirty. One-Mississippi…two-Mississippi…three-Mississippi…rattle-rattle-in the bucket…four-Mississippi…squeak-squeak in the bucket……ten-Mississippi…rattle-rattle-in the bucket……twenty-Mississippi…silence in the bucket……thirty-Mississippi. Then I carefully opened the bucket away from my face, and backed away for another thirty seconds so I
wouldn’t inhale the escaping vapors. The smell inside the bucket was a nauseating mix of mouse urine and feces. I was required to shake the bucket, and if there was any movement, repeat the gassing process as many times as necessary. I remember one breeder mouse that looked a lot like Copernicus took three
gassings to finish off.
Once I was satisfied that all the mice were dead, I knotted up the blue plastic bag like a common bag of trash and walked it back to the lab. There I tossed it into a special freezer reserved for mouse carcasses. I never found out what happened to the mice after that.
***
Sometimes I dreamed of rescuing the poor little mice. After all, the mouse colony staff
didn’t care what happened to them once their usefulness ran out. I thought of freeing the mice somewhere in the woods, since the University of Iowa Hospitals are located adjacent to a wooded area, but figured the poor, simple city mice
wouldn’t know how to fend for themselves. They had become accustomed to a daily regiment of brown gruel, and
wouldn’t know how to forage for food in the wilderness. Born a lab mouse, die a lab mouse. I considered taking a few select mice home with me to my dorm, and stealing some gruel from the lab to feed them, but since there was a strict no-pets policy in the dorms, I decided against it.
I estimate in the three months that I worked at the lab I gassed almost a thousand mice in the same five-gallon bucket. The Nazi’s killed almost six million Jews.
***
Today, mice are killed so that humans can live. Billions of mice around the country are gassed each day so that cures can be found for diseases such as Alzheimer’s. But I can’t do it anymore. Every time I gassed a new batch of mice, I remembered the graphic novel we read in high school titled
'Maus.' Each gassing reminded me of Mauschwitz, and a tear would weld up in my eye as I remembered my pet rat Copernicus who would sit on my shoulder who later died from pneumonia at the ripe old age of four. Better to leave the gassing to the real researchers, the future doctors and surgeons of America. I’d rather write about my experiences as a survivor of the mouse colony concentration camps.
{Peace}
John
