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Sometimes you have to get lost to find yourself again: an ode to the science of wood anatomy.

Updated: May 26, 2023

As I laid my eyes on the famous densitometer that created some of the most important maximum latewood density (MXD) chronologies and gazed at the wall of books containing the famous wood anatomy slides created by Fritz Schweingruber, my mind was already blown by this place, and it was only the first day of my 6-weeks here. My trip to WSL in Zurich, Switzerland entailed learning how to process wood samples for quantitative wood anatomy (QWA) from one of the most influential and prestigious wood anatomy labs in the world. To say I was falling into a pit of imposter syndrome just walking these halls was putting it lightly. But somehow, I was here, despite that it felt like my eyes were lying to me. Every single element of my next few weeks in Switzerland was unrivaled in not just my immersive learning experience, but also in a self-discovery journey that I quite honestly didn’t realize I had also signed up for.

View from WSL guesthouse

Most of my stay during my visit was in the WSL guesthouse, which ended up being a very welcoming family-like community to come home to after long days in the lab. Sure, I may have just gotten lucky with the guests that were staying there at the time, but I firmly believe that throwing a culturally diverse group of young professionals together would likely end up with a similar result. Although the United States is a melting pot, watching the Euro Cup semi-final together and tuning into the fact that we had over 7 different nationalities all sitting there together rooting for the same team was an unparalleled moment for me. Outside of the guesthouse, my life as a guest at WSL was anything but mundane. Work-life at WSL included a full day of research but also included two coffee breaks each day, one at 9:00 am and one at 4:00 pm, and lunch usually around noon. Of course, I couldn’t forget the perfect fire pit right on campus where anyone from WSL could host a gathering of work colleagues and friends and have a fun barbeque to decompress from the day. The lack of guilt from taking such breaks from work was such a breath of fresh air for my mental health and illustrates how to incorporate a work/life balance, even in an everyday work schedule, to help prevent burnout. Of course, people weren’t expected to come to every single social event as we would often get caught up in work, but the option to just take a pause—and that it was okay to do so—was such a contrast to work life back in the United States. My goal during my time at WSL was to process 19 whitebark pine (Pinus albicaulis) cores and 7 remnant Engelmann spruce (Picea engelmannii) samples up till the image analysis ROXAS program step, as the rest could be done back home in the states. I was cautiously advised that getting to that point for all my samples might not be possible. Even just learning the QWA processing methods themselves was incredibly time intensive. The learning curve combined with how producing usable slides depended on many factors with some that were not necessarily within my control (e.g. wood quality), made every single day matter.

Soxhlet extractor

Starting out with a highly resinous species meant that my first

step for QWA processing was to remove resins and other stored materials in the tracheid cells using a Soxhlet extractor. Tracheid cells must be fully filled with paraffin wax to stabilize cell structure during the microsection cutting step. Watching the extraction process was quite hypnotizing and had me reliving memories of my undergraduate days in organic chemistry lab. After letting the cores run through the Soxhlet extractor several times until the acetone was draining clear, the importance of Soxhlet extraction was obvious. All the samples had an extreme color change from what you would expect for sapwood and heartwood color difference in a resinous species, to one that was so uniform in color that it almost looked like spruce. Each QWA processing step had key details that would make or break the next QWA processing step which was honestly advantageous to be a perfectionist.

An embedded sample

When cutting cores into smaller sections for the next processing step, paraffin wax infiltration, each section had to be cut at an angle perpendicular to the ring angle. If the section was cut at an angle that was parallel to the rings, it would be extremely difficult to cross-date the sections as one whole core. When microtoming the sample sections before placing them into cassettes for paraffin wax infiltration, every section had to have the tracheid cells aligned as straight and perpendicular to the top of the sample as possible—although a simple detail easily overlooked—this was a perfect example of how one small mistake could be detrimental to producing desired high-quality QWA images. The infiltration step was one of the most time-consuming steps, but it was a matter of having to hurry up and wait on the vacuum-based infiltration machine to run through the entire 8-hour-long process. My absolute favorite step since you get to play with wax—does anybody else love to dip their fingers into melted candle wax or in the liquid wax from one of those wax warmers? —was the embedding step. The embedding station is almost a fancy machine version of a fridge water dispenser, but it dispensed liquid paraffin wax instead. The entire left side of the station was warm to keep the wax in a liquid state, and the right side was cold for the poured paraffin blocks to rest on and solidify. For each sample, I poured a tiny bit of paraffin wax into the metal container, placed the previously microtomed side of the section face down in the metal block holder letting the wax harden slightly for it to “stick” to the bottom, and filled the metal container with a rotary microtome holder cassette on top. Once the blocks were solidified, I carefully peeled them out of the metal container and hoped the entire block came out in one piece, ready to be made into microsections.


The microsection cutting step would have been my favorite if it wasn’t for me being a perfectionist and running out of patience after processing so many samples. But even still—after prepping the samples the day before and soaking them in cold water overnight—I sat there, with my eyes glued to the rotary microtome blade while slowly turning the rotary handle to see if the perfect microsection would be carved off the block. Whenever I cut a visually approved microsection, I would practically hold my breath while moving it from the blade to the warm water bath. If I somehow prevented the microsection from folding onto itself, I would take a glass slide that was thinly coated with albumin (albumin kept the sample attached to the slide during the staining process) and carefully scooped the microsection onto the slide, oriented with the long sides of the microsection parallel to the sides of the slide. As you might imagine, this is one of the most anxiety-provoking parts of QWA processing since this is where you need to make the best quality microsections possible.

Eukitt drop on a stained microsection slide

After a minimum of 2 hours in the dry oven to melt away the now not needed paraffin wax, the staining part began—also a favorite of mine because you get to see the samples basically come to life! Depending on the species I was working with, I used various amounts of 95% alcohol and xylitol soaks—these washes removed as much remaining paraffin wax in the cells as possible—and then stained them in a 1:1 ratio of safranin and Astra blue dyes. After rinsing off extra dyes with water and a quick dip into 95% alcohol again, I could for the first time see the stained pink areas of the lignified portions and the blues of the non-lignified structures! But to be able to do anything with my slides without damaging the microsections, they must be permanently fixed onto the slide. I had to hold each slide at a 45-degree angle and place one drop of Eukitt at the top edge of the sample allowing gravity to slowly pull it down across the entire sample before carefully placing the slide cover on top and putting it onto a metal sheet. I gently placed a small circular magnet on each slide so the slight pressure from the magnet squeezed out any unwanted air bubbles before placing the slides into the dry oven for two hours. My first batch of QWA sample processing was officially done—now to only repeat it 4 more times and start on the image processing stage. I cannot say it enough, every single step throughout QWA processing has such specific details and each one is crucial for correct cell detection and measurements in ROXAS. I didn’t come close to hitting every step or detail, so you can let your imagination run wild with just how long of a process this can be. But, it is all worth it when you end up with images like these!

Microsection image (blue areas are non-lignified and pink areas are lignified structures).
Lauterbrunnen valley

Although QWA processing is why I was even in Switzerland, I couldn’t help but have an adventure bucket list I was itching to get to. I had luckily made enough progress at that point in my trip to take advantage of the beautiful country I was in and take a long weekend to check off the first item on my list. A short 2-hour train ride to Lauterbrunnen, a village settled in a 72-waterfall glacial valley at the foot of the Swiss Alps, was quite literally what dreams are made of. As a self-deemed

One of the first breathtaking views of my hike to Schilthorn

adrenaline junkie in the Swiss Alps, my first full day there was spent on a physically exhausting hike that was packed full of views. Hiking from Mürren to Piz Gloria is by far one of the most memorable adventures of my life, even though, retrospectively, I probably shouldn’t have done it. But, I lived to tell the tale of hiking completely alone (as

in there was actually no one else out there at all) as the stereotypical dumbass American tourist, hiking 9 miles (of which the last 5 were completely covered in snow) up 4,700 feet elevation gain to the top of the 9,740-foot tall Schilthorn summit, climbing over the closed off fence at Piz Gloria, and getting “what the hell” looks from what I assumed were high-income tourists drinking fancy beer and wines at the site where one of the James Bond movies was filmed. To be fair, I was insanely sunburnt, sweaty, and probably quite questionable looking, especially since I basically appeared from nowhere. All I can say is that I was insanely thankful for a one-way gondola trip down the mountain back to Mürren for my train ride to Lauterbrunnen.

View from the top of Schilthorn

Despite how utterly exhausted I was by

the end of the day, the 360-degree breathtaking views all throughout the hike made every single pain that I had in my body completely worth it. With only one more almost-full day in Lauterbrunnen, what is an adrenaline junkie to do but one-up the day before, but go paragliding? I might be crazy but don’t worry, I did this as a tandem paraglider through a professional and safe company. My Lauterbrunnen-native pilot introduced himself and, on the gondola ride up to the takeoff site, explained the do’s and don’ts of being a paragliding passenger. Once he made all the safety checks and made sure I was mentally prepared for what was next, off we went, running down the hill taking a leap of faith into the wind. Thankfully the next noise I heard was the woosh from the kite filling with air, followed by my adrenaline junky cackle laughter. We only just became airborne, and I was already involuntarily smiling from ear to ear. We flew around the entire valley and climbed up to the mountain peaks with nearly every uplifting breeze that my pilot could find. There I was, sunburnt as hell from sweating off every reapplication of sunblock the day before, having the time of my life flying around the valley, looking down on the trail I probably could’ve died on the day before. To this day, I cannot articulate the sheer happiness I felt in that moment. My time in Switzerland was only possible because of researchers willing to teach and instill a newfound passion for learning and pushing the boundaries of our current knowledge. I cannot encourage graduate students, researchers, and undergraduate students enough to seek out international workshops and collaboration opportunities, as you never know what life-changing moments both in and outside of work you might experience. QWA may not always be a viable or practical option for a research study, but it is nearly impossible not to argue that the frontier field of QWA truly represents the saying, “all possibilities are endless”.

Paragliding view of Lauterbrunnen Valley

Here is where I am going to throw a bit of a curve ball at some of you and briefly mention a truly personal decision. My hope in sharing my experience is that it may provide support and insight to those in similar situations. When I began my Ph.D. program in the Fall of 2019, I had a clear end goal to become a professor. But—as many of you may relate to—the Covid-19 pandemic and other drastic life-changing events were catalysts for some extreme introspection into who I am, what my true aspirations are (without my mind being clouded by opinions of others), and my physical, mental, and emotional health. After over a year of navigating guilt and constant internal debate, I finally allowed myself to admit that I was not in the program for the right reasons anymore. I realized I was only continuing in it because I wanted to prove my own intelligence and self-worth to others and to myself. My perception of myself was directly related to my academic successes and whenever I had an academic “win”, I could practically feel my ego become grossly inflated. I began to lose sight of what things in life I truly valued and why I started the program in the first place. I am far from a perfect person. I know I played a large role in my personal evolution, and I am still navigating where I want to go from here. But, once I realized I was sacrificing my mental, emotional, and physical health all because I couldn’t stand the thought of quitting something, I had to set my ego aside to be truly honest with myself. Mastering out of my program was the right choice for me. However, for anyone who is thinking of leaving a graduate program only because it is hard—don’t. While in my Ph.D. program, I pushed myself in a way I never had before. My own personal growth, multi-disciplinary knowledge base, and even career aspirations would be drastically different had I left the program when it got hard. Even retrospectively, I have zero regrets about my journey as a Ph.D. student. Exploring curiosities is never a waste of time. No matter what career or program or journey you may be in—remember to pause, check in with yourself, and stay humble.



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