When Just was young he became dreadfully sick for six weeks with typhoid. Once the fever passed he had a hard time recuperating, his memory had been greatly affected. He had previously learned to read and write with a great amount of excellence for someone so young. Now he had to go through the process all over again. His mother had been very sympathetic in teaching him but after a while she gave up on him. Then one day he read his first page- by himself, this seemed miraculous. He kept his new secret to himself for a month before telling his mother because he felt she had hurt him with her unreasonable expectations.
Hoping Just would become a teacher, his mother sent him to an all-black boarding school in Orangeburg, South Carolina at the age of thirteen. Believing that schools for blacks in the south were inferior, Just and his mother thought it better for him to go north. At the age of sixteen, Just enrolled at a Meriden, New Hampshire college-preparatory high school, Kimball Union Academy. Tragedy struck during Just's second year at Kimball when his mother died. Just decided to return home after his second year at Kimball for a visit only to hear that his mother had been buried an hour before he arrived. Despite this hardship, Just completed the four-year program in only three years, was elected to Phi Beta Kappa and graduated in 1903 with the highest grades in his class.
Just went on to graduate magna cum laude from Dartmouth College in Hanover, New Hampshire.Just won special honors in zoology, and distinguished himself in botany, history, and sociology as well. He was also honored as a Rufus Choate scholar for two years.
Just spent at least 20 summer sessions at Woods Hole, he learned to handle the material with skill and understanding, in time he was in great demand for those looking for advice and assistance in the field of biology. In 1915, Just took a leave of absence from Howard to enroll in an advanced academic program at the University of Chicago. That same year, Just, who was gaining a national reputation as an outstanding young scientist, was the first recipient of the NAACP's Spingarn Medal on February 12, 1915. He began his graduate training at the marine biological laboratory in 1909 with the course in marine invertebrates and in 1910 in embryology. In 1911-1912 he was a research assistant, his experiments focused on marine eggs, fertilization and breeding habits of the sea-urchin Arbacia. His duties at Howard delayed the completion of his work and receiving his Ph.D. degree at the University of Chicago until 1916. In June 1916, Just received his Ph.D. in experimental embryology, with a thesis on the mechanics of fertilization, from the University of Chicago, becoming one of the handful of blacks who had gained this degree from a major university. By the time he got his Ph.D. in 1916, he had already co-authored a paper with Dr. Lillie.
Just, however, became frustrated because he could not attain an appointment to a major American university. He wanted a position that would provide a steady income and allow him to spend more time with his research. Just’s scientific career was a constant struggle for opportunity for research, the breath of his life. He was condemned by race to remain attached to Howard, an institution that could not give him full opportunity to ambitions such as his. The same year, he conducted experiments at the prestigious zoological station 'Anton Dohrn' in Naples, Italy. Then, in 1930, he became the first American to be invited to the Kaiser Wilhelm Institute in Berlin, Germany, where several Nobel Prize winners conducted research. Altogether from his first trip in 1929, Just made nine visits to Europe to pursue research. Scientists treated him like a celebrity and encouraged him to extend his theory on the ectoplasm to other species. Beginning in 1933, Just ceased his work in Germany when the Nazis began to take the control of the country. He relocated his European-based studies to Paris.
Just authored two books, Basic Methods for Experiments on Eggs of Marine Mammals (1922) and The Biology of the Cell Surface (1939), and he also published several scientific papers relating to cell cytoplasm. Although Just’s experimental work showed an important role for the cell surface in development, it was largely and unfortunately ignored. This was true even with respect to scientists who emphasized the cell surface in their work. It was especially true of the Americans; with the Europeans he fared somewhat better.
In 1996, the U.S. Postal Service issued a commemorative stamp honoring Just.
Beginning in 2000, the Medical University of South Carolina has hosted the annual Ernest E. Just Symposium to encourage non-white students to pursue careers in biomedical sciences and health professions.
In 2002, scholar Molefi Kete Asante included Just on his list of the 100 Greatest African Americans.
Just believed that "life as an event lies in a combination of chemical stuffs exhibiting physical properties; and it is in this combination, i.e., its behavior and activities, and in it alone that we can seek life."