As part of the multi-step workflow that Dr. Maier’s students follow to validate the accuracy of the D100, they first have to image the dispensed cells in a well plate. “That imaging part is very important because it shows that the dispenser from HP was able to dispense intact, viable cells,” Maier says. After imaging, the sample is lysed with either a freeze/thaw cycle or with heat and processed for analysis before the mass spectrometer can do its job.
The HP software would originally put an “X” on the screen in the wells that did not have an intact cell in it, but now there’s a function called the “junk well,” where all the non-intact cells go to die. Of the 384 wells in the plate, about 90% emerge with an intact, viable cell, HP’s Nielsen says. “The junk well was an improvement to our performance that we made partially based on feedback from users like [at] OSU,” he says.
Both Stanisheuski and Ebrahimi say that having access to the HP D100 has re-energized their work. “It’s completely changed my whole perspective about my research,” Ebrahimi says. “There’s a lot of nuance there that needs to be discovered.”
Ebrahimi is working with PC12, neuron-like cells, to see how they “differentiate” after adding nerve growth factor (NGF). Over the course of six days, she tracks protein signatures as the cells change size, shape, and functions in response to the NGF. “You want to see the progression of cells. What actually changes during that process? What proteins are being expressed more or what proteins are being expressed less?”
Answering these questions now will open the door to Ebrahimi and other scientists, in the future, using the HP D100 to study neurodegenerative diseases like Alzheimer’s or Parkinson’s. Ebrahimi is also using the D100 to isolate cells to determine their lipid composition, which are important in a lot of biological pathways. (Technically this is not proteomics, but still interesting for future research in how individual cell metabolism affects the body.) Stanisheuski, and a team of co-authors — including Ebrahimi and HP’s Jang — will soon be submitting a paper on their work with the HP D100 to Frontiers in Chemistry.
In the near future, Dr. Maier hopes she and her team will be able to use the D100 to study the different cell types that make up a tissue, such as in a tumor. “We don’t really know much about how the different tumor cell populations biologically differ and become aggressive cell types,” she says. “A deeper understanding of the biology of these different cell types has the potential to inform treatment strategies for patients with cancers.”
Stanisheuski, for one, can’t wait to begin: “We’re excited about it because the technology actually works.”