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Henrietta cells were harvested.

On Februrary 8th 1951, Henrietta's cells were harvested during an operation in which the doctors put radium in her cervix to destroy her cancer cells. George Gey, the head of tissue culture at John Hopkins, would find that cells from Henrietta's tumor in her cervix reproduced indefinitely.

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The HeLa cells are used to test the polio vaccine.

Jonas Salk had already figured out how the polio vaccine would work, he just needed to test its safety. Normally, scientists would have taken cell from monkeys, but monkeys were expensive. In order to create the vaccine in the shortest amount of time possible, Salk would need easily produced cells that were susceptible to the polio virus, but wouldn't be killed by it. It just so happened that the HeLa cells were very susceptible to the polio virus, easy to produce, and hard to kill, making them perfect for the task.

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Scientists discover that human cells have 23 pairs of chromosomes

A lab mistake which involved mixing HeLa cells with a wrong liquid allowed researchers to see and count each chromosome clearly in HeLa cells they were working with for the first time in history. This accidental discovery led scientists Joe Hin Tjio and Albert Levan to develop better techniques for staining and counting chromosomes. They would become the first to accurately describe that humans have 23 pairs of chromosomes rather than 24, as was previously believed. This would prove important for the study of developmental disorders such as down syndrome that involved the number of chromosomes.

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The HeLa cells become the first cells to be successfully cloned.

Theodore Puck and Philip Marcus successfully clone
HeLa cells at the University of Colorado, Denver.

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HeLa cells are used to understand the effects of x-ray and radiation on human cells.

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Scientists create a test that determines whether a cell is cancerous or not.

The HeLa cells were used to help develop a test to differentiate between cancerous and non-cancerous cells. This test proved to be so reliable scientists still use it today.

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HeLa cells become the first human cells to be sent to space

They were sent to space on the Soviet satellite, Korabl-Sputnik. Later they would also be put on Nasa's Discoverer XVIII satellite. The studies on these cells would be the initial clues to how humans would react to the radiation in space.

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Scientists infect HeLa cells with Salmonella

Infecting HeLa cells with salmonella is discovered to be a cost effective way to test studies on the disease. The knowledge received from these studies will help develop new ways to diagnose and treat the disease.

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HeLa cells make strides against cervical cancer

Scientist  Harald zur Hausen found that the HeLa cells from the original biopsy contained HPV-18, which was later found to be the cause of the aggressive cancer that killed Henrietta Lacks. This discovery eventually led to the development of the first hpv vaccine, the first vaccine to prevent cancer. His work would later lead to a Nobel Prize in 2008.

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Scientists infect HeLa cells with HIV

HeLa cells are infected with HIV to study its effect on human cells. This is very important step in understanding how to fight the virus. The HeLa cells have been infected with many other diseases such as herpes, Zika, measles, and mumps. HeLa cells have been able to help scientists better understand how to fight these diseases.

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Seeing how tuberculosis makes people sick.

Scientists use HeLa cells to see for the first-time, at the molecular level, how tuberculosis makes people sick. This innovation is very useful for the future development of more effective treatments and vaccines.