Newswise — COVINGTON, Kentucky, July 22, 2019 -- Two experiments on the International Space Station examined how different crystal formations can be grown in a microgravity environment. One of the experiments was designed by six prize-winning students from Wisconsin, who were looking to compare growing salt crystals in space to growing crystals on Earth. The other experiment tested new advancements in methods and hardware to direct protein crystal growth by astronauts on the space station. 

Both experiments will be featured during a session at the 69th Annual Meeting of the American Crystallographic Association, being held July 20-24, in Covington, Kentucky. Ilia Guzei, a senior scientist at the University of Wisconsin-Madison, and Kristofer Gonzalez-DeWhitt, a medical and doctoral student in the UCLA-Caltech Medical Scientists Training Program, will present their results as part of a broader talk on microgravity molecular (organic and inorganic) crystal growth. 

A group of high school, middle school, and home-schooled students, ages 12 to 17 and under the guidance of Guzei, designed the experiment to grow potassium dihydrogen phosphate, a safe, inexpensive and easy-to-crystallize salt. They achieved their results by cooling saturated salt solutions from 20 degrees Celsius (68 degrees Fahrenheit) to 4 degrees Celsius (40 degrees Fahrenheit) over a week in the International Space Station National Lab. 

“We wanted to find out if our space experiments would yield the same polymorphs that are observed on Earth,” Guzei said. “In addition to growing crystals, the students will learn about solution chemistry, compound solubility, purification, crystallization, optical microscopy and microgravity. In the process, the students will adopt an advanced vocabulary and learn to work in teams, keep detailed records of their progress, communicate with their teammates and follow good laboratory practices.” 

While the experiment showed similar results in space as on the ground, Guzei said the students were exposed to the special characteristics of engineering, research and operations in a space environment. 

“(The students) collaborated with the Center for the Advancement of Science in Space, the sole manager of the International Space Station U.S. National Laboratory, in order to develop the ground crystallization experiments into an on-orbit experiment by the students,” he said. 

He said future plans will be discussed at the ACA conference. The students were winners of the annual 2018 statewide Wisconsin Crystal Growing Contest. 

In a separate experiment, space station crew members were asked to grow protein crystals in real time using technology that recently made such research possible. Gonzalez-DeWhitt said the focus of the research was finding new methods for future microgravity experiments but also testing those methods to determine if they were a worthwhile approach. 

Three crew members successfully grew lysozyme crystals in the crystallization plates under the real-time direction of investigators located on Earth. The earthbound scientists directed adjustments to the conditions of the experiment to further explore real-time crystallization onboard the space station. 

“The astronauts did not receive any ground training prior to conducting the experiment on ISS,” Gonzalez-DeWhitt said. “They were able to skillfully follow the protocol without any issue. As much as I would like to credit that to a well-written and detailed protocol, the truth is that all of the ISS crew members are extremely talented. They can learn new skills incredibly fast.” 

Gonzalez-DeWhitt plans to talk about the challenges investigators face when conducting protein crystal growth experiments, how the results of the space station experience could alleviate some those challenges, and what the future could be for further experiments in space. 

“A real-time protein crystal growth approach to microgravity protein crystal growth is a potential option for future investigators to consider,” he said. “The future goal is to establish a kind of mail-order system whereby experimenters would provide reagents, materials, and protein and then ISS crew members would assemble crystallization experiments.” 

Gonzalez-DeWhitt said crystallization experiments have been going to space since the early 1980s, but this is the first time that scientists are exploring the possibility of a real-time approach to protein crystal growth. 


The session, “Crystallization on the International Space Station,” will be held at 1:30 p.m. EDT, Monday, July 22, in the Learning Center at the Northern Kentucky Convention Center. 


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The American Crystallographic Association was founded in 1949 through a merger of the American Society for X-Ray and Electron Diffraction (ASXRED) and the Crystallographic Society of America (CSA). The objective of the ACA is to promote interactions among scientists who study the structure of matter at atomic (or near atomic) resolution. These interactions will advance experimental and computational aspects of crystallography and diffraction. Understanding the nature of the forces that both control and result from the molecular and atomic arrangements in matter will help shed light on chemical interactions in nature and can therefore lead to cures for disease. See