Sorting chloroplasts, pollen grains and coffee grounds
Let’s say you want to sort people according to the colors they dye their hair. You can line them all up, single file, and send the blue-haired ones to one place, the undyed hair to another, and so on.
This is what we do with cells in a process called flow cytometry. You stain the cells, and the machine detects the color as they pass through. This is a way to study single cells. For example, with the right kind of stain, we can ask how many cells in a sample are infected, which cause the virus, and how many are not. We can sort all healthy cells in one test tube and all infected cells in another.
As manager of the Flow Cytometry Facility at Cornell University in Ithaca, New York, I clean and calibrate machines—here I am, working under the hood on a purple-fronted machine. To test this, I use a suspension of beads, the green liquid in a cylinder. Things like humidity and air pressure can affect these sensitive machines, so it’s always a challenge. I like challenges.
Our facility was closed in March and April due to the pandemic, but then we got the green signal to open it to people working on the virus. A lab is working on a vaccine that has been tested on animals, and we helped the team sort and count the animal’s immune cells. I go inside to prepare the machine and meet the person who brought the samples, but I can also monitor things from home.
I grew up in Guanajuato, Mexico, before moving to California in 1991, where I met my husband and trained as a science teacher. Now, I teach scientists about flow cytometry and help them plan their experiments. Every experiment is different: they can sort out bacteria, pollen grains, chloroplasts, spores, you name it. One person wanted to sort out the coffee grounds; Another was brought to the dish-grown feather for laboratory analysis.
