“The Spirit of the MBL”: An Improvised Microscope and 25 Years of Developmental Biology in Latin America

Two lines of people, one standing and one sitting, pose in front of a building with glass windows. A mountain is visible in the background.

The class photo for the 2025 Practical Course in Developmental Biology, held in Quintay, Chile, in January. MBL Director Nipam Patel is second from right in the back row. Courtesy: Roberto Mayor (far right, back row)

By Alex Megerle February 18, 2025

They were thousands of miles from home when they realized something was missing.

It was early January and Marine Biological Laboratory (MBL) Director Nipam Patel was in the small village of Quintay, Chile, together with MBL Research Scientist Matthew Parent. With them was a microscope they had shipped all the way from Woods Hole, Massachusetts, to use in a hands-on developmental biology course. This was no commercial scope. This was a custom, home-built device, constructed on an optical breadboard—a plate specifically designed for prototyping optical equipment. Parent had just unpacked the microscope’s various pieces and Patel was preparing samples to test it.

“And then Matthew discovered that the power supply hadn’t been packed into the case, and it was still sitting [at the MBL],” Patel said.

The course was set to begin in a handful of days. The story of what happened next is filled with the ingenuity, collaboration, and commitment to education that defines the MBL.

See A Need, Fill A Need

It began in Woods Hole in 1988, when Roberto Mayor, a PhD student from Chile, came to the MBL to attend the Embryology course.

It would not be overdramatic to say the experience changed his life. Mayor was completing his doctorate degree in mouse development at the time, but after learning about amphibian development at the MBL, decided to pursue that subject for his postdoctoral work. Now a renowned developmental biologist at University College London, Mayor continues to study amphibians to this day.

But his time at the MBL didn’t just alter Mayor’s career trajectory—it also opened his eyes to the impact that courses like Embryology could have on a student. The seeds it planted would start to sprout after Mayor completed his postdoctoral work in the United Kingdom and returned to Chile to find an alarming reality.

“I was the only one doing developmental biology using molecular biology, I mean modern approaches, in the whole country,” he said. “There was nobody else. And a very similar situation was likely in all Latin America, although we did not know what was going on in our neighbor countries at that time.

“So, there was really a need for teaching developmental biology at a higher level.”

That was the motivation Mayor needed to start a “mini Woods Hole course,” as he called it, which kicked off in his home city of Santiago in 1999 with the help of a group of developmental biologists at the University of Chile.

The course, which takes place biennially, is officially named the Practical Course in Developmental Biology. In a 2021 paper in The International Journal of Developmental Biology, Mayor explained its basic format: “a combination of laboratory experiments using different animal models and lectures given by world leading developmental biologists that cover the paradigms, questions, and technologies of modern developmental biology.”

He noted this structure has stayed the same despite the name and location of the course changing over time. It moved to its current location in Quintay in 2010, taking up residence in a marine biological station owned by Andrés Bello University (UNAB).

Over the years, resources for the course have been provided by UNAB, the European Molecular Biology Organization (EMBO), the MBL, Universidad Mayor, and other organizations. 91�鶹�� contributions have taken various forms (including funding the course in a year when EMBO did not), but perhaps none have required more resourcefulness than the microscope that traveled south this past January.

A class photo for the 1988 Embryology course at the Marine Biological Laboratory. Roberto Mayor is third from right in the front row.

MacGyver-ing a Microscope

Organizers encountered a significant hurdle while preparing for this year’s course. They had access to good, but relatively simple, teaching microscopes, Patel explained, but it appeared they would not have access to more advanced microscopes that the students would need to run experiments.

Patel brought the issue to the attention of MBL Investigator and Imaging Scientist Abhishek Kumar, who put forward an idea: build a line-scanning confocal microscope that could be disassembled, shipped to Chile, and then reassembled on-site.

A confocal microscope is a type of scope that can produce three-dimensional images of a fluorescent sample. It does this by scanning the sample in layers, having removed out-of-focus light, and then stacking those images on top of each other, Parent explained. The 91�鶹�� has several commercial confocal microscopes across campus, and a state-of-the-art home-built line-scanning confocal in its Imaging Innovation Center, where both Kumar and Parent work to design, build, and disseminate new microscope technologies.

It only took Kumar and Parent a single afternoon to construct a simpler version of the MBL’s confocal that could nonetheless serve the course’s needs. They then split the machine into sections for transport.

“All these microscopes can be taken apart—it’s just a matter of how complicated it is and how long it would take to put it [back] together,” Parent said. “So as much as possible, we tried to leave the microscope assembled during shipping.”

Getting a microscope through Chilean customs is not a simple process, which put the team in a rush to get the equipment packed and shipped in time for the course. In the hurry, the power supply that would power the microscope’s lasers was left behind. Upon discovering the oversight in Chile, Patel and Parent weighed their options.

“Our first instinct was to just overnight it from [Woods Hole] or to reach out to Coherent—because they’re Coherent lasers—and see if they had any sort of support in Chile,” Parent said.

After some investigation, neither approach looked promising. Coherent, a laser company headquartered in Pennsylvania, couldn’t help them before the course was supposed to start. MBL Research Scientist Rylie Walsh tried to mail the power supply to Chile, but it got caught up in red tape. With their initial avenues exhausted, Parent began to brainstorm alternatives and pulled up the specs for the laser control box.

Under normal circumstances, the laser box would be plugged into a power supply via a cable with a specific type of connector on the end. That specific connector, Parent found, was very similar to the connector on the end of a cable from a computer power supply—a supply that matched the power requirements of the laser box. The next idea followed naturally—could they run the laser box using a computer power supply?

The team bought one, but the problems kept coming. The connector turned out to be too big to plug into the laser box, so Parent cut away the connector’s housing to access the individual pins. These were also too large, so using pliers, Parent crimped the pins so they could fit properly into the laser box.

Commercial vs. Home-Built Microscopes:

Commercial microscopes, such as those sold by Nikon, Zeiss, Leica, and other companies, are established systems that offer ease-of-use and vendor support. Home-built microscopes, on the other hand, are an investment in time and energy to construct, but can be designed for specific applications and tend to be less expensive than commercial scopes. They also give designers and users the chance to understand the microscope's design and learn how the technology actually functions, with opportunities to adapt it for particular purposes.

Point- vs. Line-Scanning Confocal Microscopes:

A point-scanning confocal microscope collects light from a sample one point at a time, whereas line-scanning confocal microscopes collect light from every point on a line simultaneously. Line-scanning microscopes can image faster than point-scanning microscopes but remove less background signal, resulting in images with slightly lower contrast.

Three oval shapes arranged in a column. The top is yellow, purple, and blue; the middle is purple and blue; the bottom is yellow and blue

Fly embryo imaged on the confocal microscope 91�鶹�� scientists built for the course. Muscles are in purple, the peripheral nervous system is in yellow, and the central nervous system is in blue. Credit: 2025 Practical Course in Developmental Biology students

Parent needed two more tricks up his sleeve—wrapping the pins in electrical tape to prevent them from shorting out and modifying the power supply to work without being connected to a computer—but finally, the moment came to find out if the improvised solution actually worked. Parent jokingly recalled the team’s thoughts prior to flipping the switch.

“We’re like, ‘Either this is going to be really neat and it’s going to turn on, or something’s going to short out and we’re going to be in trouble,’” he said.

It was the former.

“It was definitely very much a MacGyver kind of operation,” Patel said. “But it worked great.”

The microscope performed just as they needed it to, Patel added, with the extra benefit of an open-concept construction that let students see how the machine functioned. The saga embodied “the spirit of the MBL,” Patel said: Whether in Woods Hole or Quintay, when things go wrong in a course, faculty need to find an answer in a limited time.

“The whole course is only two weeks long, and we have only two days for our section of the course,” he said. “So you just gotta figure it out.”

A computer monitor, keyboard, and mouse on a table along with microscopy equipment. An adjacent table positioned behind the first also has microscopy equipment on it. — The line-scanning confocal microscope built by 91�鶹�� scientists for the developmental biology course in Quintay, Chile. Courtesy: Nipam Patel

A multicolored ring on a black background. The left half is primarily dark blue, while the right half is a mix of light pink, magenta, and green. — Fly embryos showing Hox gene expression, imaged during the 2025 developmental biology course in Quintay, Chile, using the line-scanning confocal microscope built by 91�鶹�� scientists. DAPI (nuclei) in blue, Ubx in green, abdA in red, AbdB in grey. Ubx, abdA, and AbdB are Hox genes in fruit flies. Credit: 2025 Practical Course in Developmental Biology students

Movie of a zebrafish embryo generated using the line-scanning confocal microscope built by 91�鶹�� scientists for the 2025 Practical Course in Developmental Biology in Quintay, Chile, this past January. Blood vessels in green, photoreceptors in red, DAPI (nuclei) in blue. Credit: 2025 Practical Course in Developmental Biology students

An MBL-Inspired Education

This year, 20 students came to Quintay. Nineteen were from Latin America, representing seven different countries: Chile, Brazil, Argentina, Uruguay, Peru, Mexico, and Colombia.

The students—primarily early-career researchers and graduate degree candidates—studied five different animal models over two weeks: fruit flies, zebrafish, chickens, frogs, and sea urchins. The course’s emphasis on multiple models was inspired by the MBL Embryology course, Mayor said, which covers a breadth of organisms rather than focusing on just one.

Though he was involved earlier on, Patel has been a faculty member for the current form of the course since 2014. This year, he taught the fruit flies module. Numerous others from the MBL Embryology community have also taught in the course, including Embryology faculty David McClay (this year), Embryology faculty David Sherwood (last year), and MBL Fellow and former Embryology co-director Alejandro Sánchez-Alvarado (last year).

Parent primarily ran the confocal microscope supplied by the MBL. Though the course ended up receiving a light-sheet microscope from elsewhere, too, the students benefited from having Parent himself on-site.

“I spent a lot of time with the students trying to explain how the microscope worked—obviously helping them image their samples, but also trying to teach some very basic microscopy,” Parent said. “Even this odd-looking thing is a microscope, even though it doesn’t really look like a microscope.”

“It was not expensive to build,” he added. “And with a little bit of know-how, it’s possible to build these, and they function just fine.”

In addition to its contributions of expertise and equipment, the MBL offers the top two students in each Quintay cohort admission to the Embryology course in Woods Hole.

“And we are very proud to hear that usually they perform very well,” Mayor said. “They’re among the best students in that course.”

Many people have given their time and expertise to help the course in Quintay thrive; Mayor highlighted support for this year’s iteration from Fernando Faunes of UNAB and Leonardo Valdivia of University Mayor. Mayor alone, however, has been with the course since its inception. He keeps busy with a variety of roles, including instructor, administrator, and even facility staff. The workload and logistical hurdles of organizing the course can be burdensome, and Mayor described how every time he does so, he finds himself claiming it will be his last year.

“And then the courses start and the students arrive, and it’s so exciting to see all the students so motivated,” he said. “And they start working at eight in the morning, they finish at 3 AM the next day, and I say, ‘Oh, this is great. I want to lead that next year again.’”

A coastal town arranged on a hill on the right, with a small bay on the left. — Quintay, Chile, where the 2025 Practical Course in Developmental Biology was held in January. Courtesy: Nipam Patel

An open space in the foreground with a whale skeleton on the ground on the right. Two cars and a boat are in a parking lot in front of a building. Hills and buildings are visible in the background. — The marine biological station in Quintay, Chile, owned by Andrés Bello University (UNAB), where the 2025 Practical Course in Developmental Biology was held. Courtesy: Nipam Patel

Two people walk toward each other in the foreground. In the background, a line of people stand atop a platform on top of what appears to be a stone wall. — Students in the Practical Course in Developmental Biology take in the sunset in Quintay, Chile. Courtesy: Nipam Patel

A Lasting Legacy

Faculty and students celebrated the course’s 25th anniversary during their traditional symposium this year. Rather than the typical faculty, symposium speakers were course alumni, representing cohorts from recent years all the way back to the inaugural class of 1999.

It was that first year when students asked their course leaders to organize a network of developmental biologists working in Latin America, Mayor said. That quickly evolved into the Latin American Society of Developmental Biology, an active organization that has held 11 international meetings since 2003. Mayor recalled how, when the course began, no one knew who was studying developmental biology in neighboring countries.

“And now, for the young people, that is unthinkable,” he said. “Because everybody knows each other through the Latin American Society of Developmental Biology.”

Where the course goes from here is still being determined. Mayor emphasized that its success depends on collaborating institutions; while those partnerships provide for the course’s present, they may also shape its future. This year’s co-hosting universities have been suggesting new directions to take, Mayor said. Introducing more cell biology into the curriculum is one avenue that remains undecided.

Other parts of the future are more concrete—the MBL will continue to do what it can to support this remarkable course and the amazing students that it trains.

91�鶹�� traveling microscope is now on its way back to Woods Hole, Parent said. There are tentative plans to send it back to South America in the future, continuing the MBL’s legacy of furthering scientific discovery around the world.

Source: Mayor, R. (2021). 20 years of the “Practical Course in Developmental Biology” in Latin America: from Santiago to Quintay, via Juquehy, Buenos Aires and Montevideo. The International Journal of Developmental Biology, 65(1-2-3), 83-91.