Before you look: How cleanrooms ensure reliable results.

Prepping for Resolution

Are we seeing what we think we’re seeing?

That’s a key question for any good scientist — but none more so than those who use the world’s most powerful microscopes. In the microscopic world, bad data finds its way into a study on a breath. Contaminants are carried on the air, in hair, and on sleeves or neckties. If the wrong particle makes its way into a sample before that sample goes under the microscope, it’s hard to tell what was supposed to be there and what wasn’t.

The solution is the cleanroom.

“What makes us important,” Kristie Diebold says, “is a working environment where you don’t have tons of particulates around you like an ordinary lab might have.”

As a senior cleanroom microscopist at McCrone Associates, it’s part of Diebold’s job to help project managers study the right samples, in the most effective possible way. She demonstrates her method with a hypothetical example: Suppose 10 samples arrive at McCrone in vials. Each vial contains a colorless fiber — the contaminant a client wants to identify.

A project manager’s first challenge: Get those samples ready for investigation — but don’t introduce additional contaminants along the way.

“They don’t want to get any other types of particulate in — that’s why it’s coming to us in the cleanroom,” Diebold says. “We can go ahead and filter those samples and make sure we’re not adding any other type of particulate.”

Diebold’s process is meticulous: She’ll take a close look at the samples with her instruments before she filters them, then filter them in the effectively particulate-free enclosure of an ISO Class 5 hood. On filtering, she’ll take a second look at the samples and any particles recovered from them.

Then it’s time to make decisions.

What kinds of particles do these appear to be? What substrate would be best for viewing them? Diebold decides the most effective ways to mount and view the particles, then sends the mounted samples back to the project manager for further analysis.

That means it’s never just one scientist working on a challenge — the cleanroom is always sharing perspectives with other scientific staff to enhance a project.

“It’s nice to work on my projects and be able to talk with that project leader,” Diebold says. “You feel comfortable talking to everybody around you and you problem-solve together.”


Kristie J. Diebold is a senior cleanroom microscopist at McCrone Associates and an instructor with Hooke College of Applied Sciences. Her work in the cleanroom involves microscopical analysis of particles in micrometer and sub-micrometer size ranges, including manipulation, characterization and preparation for instrumental ultra microanalysis. Before joining McCrone, Kristie was certified as a Medical Technologist in Immunology to conduct cancer research at Rush University Medial Center. She has been with McCrone since 1998.