4 Signs You Earned Your PhD in the 90’s
I turned 41 this year, and for some reason, 41 seems more of a milestone to me than 40. Or if not quite a milestone, it has been a chance to reflect on the incredible amount of time that has passed. This summer will be my 18th wedding anniversary! 18 years – can you imagine? It seems like only a little while ago we were dodging the torrential rains as we scurried in our wedding finery into and out of the church.
I was also amazed to admit to myself that I earned my PhD 15 years ago! 15 years is a long time, lab-wise. While research often moves at a snail’s pace, breakthroughs will happen once in a while and revolutionize our thinking and the way we do things.
Being a lab child of the 90’s, there are several advances I can point to. If you worked towards your PhD in the 90’s, you would probably also recognize these:
1. I gave my thesis talk using slides. Yup, I dragged a slide carousel to my thesis talk and kept it hidden so my classmates wouldn’t slip in a slide containing a compromising picture of me (as they had been known to do). Interestingly, we did have PowerPoint, but we only used it to design slides and then print them out. Using this process you had to make sure you had your talk figured out and all slides printed well before the day of your presentation. Your talks also tended to be more static because often you didn’t want to put the energy in to make more slides.There were no last-minute changes like there are now.
While the current use of computers for talks makes a lot of things easier, the new kids are missing out on some time-honored traditions. Like sticking slides into other people’s carousels, or the comic relief (that served to wake the audience up) when a slide was put into the carousel in the wrong orientation, or dropping your slide tray minutes before your talk and trying to frantically put them in order. Ahhh good times.
2. Glowing animals were novel. One of the greatest discoveries I remember taking place during my graduate school years was the cloning of green fluorescent protein (GFP). GFP is a protein isolated from jellyfish that naturally fluoresces. Once it had been cloned, scientists began hooking it up to cellular proteins and putting it back into cells to make glowing cells. It was only a matter of time until they made whole organisms that could glow. At the time, the introduction of each new species of GFP animal was broadly published and met with much excitement. Today, some of these animals are commonplace.
3. I knew how to “pull” a cesium band. There were no quick DNA column prep kits for us. We had to isolate DNA the old-fashioned way! It was almost as painful as walking to and from school uphill both ways in blizzards and hot-blinding sunshine.
In the 90’s we didn’t isolate our DNA in 4 hours without hazardous chemicals. We took our time and exposed ourselves to dangers. The most precarious part of the protocol was the cesium banding. A solution containing your DNA was mixed with cesium chloride and ethidium bromide. Cesium chloride is slightly toxic and can lower the concentration of potassium in the body, irritate mucus membranes and cause asthma. Ethidium bromide is used in the prep because it sticks to DNA and will glow when under UV light (allowing us researchers to see where the DNA is) . You would probably guess that things that stick to DNA can be bad, and ethidium bromide is classified as an agent that can cause cancer and mutations.
Your DNA/toxic solution was then loaded into plastic cylinders and you used something that was about as high tech as an EasyBake oven to melt the top of the tube closed. Once closed, you “balanced the tubes” by weighing them to make sure none of them would become flying rockets in the next step. You then spun the DNA for 24 hours at high speeds using an ultracentrifuge. Our ultracentrifuge was persnickety and we always stood behind a wall while the machine got up to speed. It was a safe place to stand in case your tubes weren’t balanced just right. Because if they weren’t, they would pop off the rotor holding them, ricochet around the inside of the machine, and I was once warned, could cause the rotor to fly up and out of the centrifuge punching a hole through the machine.
And the fun was just starting. The next day you had to carefully take the now pressurized tubes into the dark room, make sure none of them had leaked, turn off the light and shine a UV light on the tubes to determine where your DNA “band” was floating inside the tube. Warning: UV lights can cause sunburns and retina damage if you stand under them or don’t wear safety glasses. Once you found your band, you then stuck a needle into the side of the tube (not all the way through the tube!) to withdraw your DNA. Yes, I did make one trip to health services with a labmate when she got sprayed by liquid spurting out of the tube.
4. I ran my own sequencing reactions and gels. These days if researchers need to know the sequence of some DNA, they drop the purified DNA (isolated in 4 hours without harm!) at a “sequencing facility” where some magic occurs and in a day or 2 receive a computer file containing the sequence. In the 90’s we had to make the magic happen ourselves. If we survived isolating the DNA, we mixed the DNA with a bunch of reagents and some radioactivity, and then took that mixture and put it onto something called a “gel” that would separate the DNA by size. Throughout the process, everything became radioactive and you had to exercise a lot of caution. Often people in our lab were seen doing the intricate ballet of trying to carry a large DNA sequencing apparatus filled with liquid from the bench to the sink without spilling out the radioactive liquid. Also, pouring the very large gels was an exercise in extreme patience.
I know if I think harder I can come up with many other signs of the 90’s being my formative lab years. How about you, my scientist friends? Any special things you remember about lab life in the 90’s?