Environmental monitoring plays a key role in ensuring our patients' safety and the efficacy
of the products we make. Think about it - when was the last time you swallowed some medicine or
got a vaccine injected in your arm? How many microbes do you think were in that product?
Five? Ten? A thousand? Of course we can't allow that. Let's test different areas of our lab to
see if microbes are present. You may be thinking - hey we clean the lab every day. It's one of the
first things we learned in this class, and you're right. So where do these microbes come from?
I'll give you a hint because it's the same person's fault every time . Their name rhymes with
...whatever your name is. But don't be too hard on yourself. Humans are naturally sheddy, but
we can use an environmental monitoring program to prevent us from contaminating our product.
Always make sure to wear your PPE - lab coat, gloves, and safety glasses. In today's lab,
we're going to demonstrate some common ways to test our personnel, surfaces, and the air.
Let's start with personnel monitoring. Dip a cotton swab into a tube of sterile
TSB - that stands for tryptic soy broth. Choose a part of your body to test like your nose, ear,
mouth, or your skin. Cassi here is going to test her forehead. Rotate the swab around three or four
times, spinning it so that the entire tip comes into contact. Now streak the swab against the TSA
plate in a zigzag pattern while rotating the tip. TSA stands for tryptic soy agar - it's like food
for microbes. If there are any present they're going to grow, and we'll be able to see them.
Cover the plate, and label it. Then place it upside down in the incubator at 32 to
37 degrees celsius for at least 18 hours. We'll check back on this plate in a moment.
Let's do another personnel monitoring test, this time we'll see how clean your hands are.
Place your four fingertips on the plate. Then swipe your thumb across the surface
to the left or right - yeah like on tinder. Cover and incubate this plate too.
Now let's do some surface monitoring with a RODAC plate/ RODAC stands for replicate organism
detection and counting - that's a mouthful which is why we just say RODAC. Choose a place in your
lab that you want to test. Cassi here is going to test this lab workbench. Open the plate and gently
touch the agar against the table. Slightly rock the plate back and forth to make sure
there's complete contact. Now close, label, and incubate the RODAC plate with the others.
And then spray the surface you tested with 70 isopropyl alcohol and wipe it clean. Air
sampling is our final test, and we're going to use two machines simultaneously to see how many
particles are in the air at this workstation. A laser particle counter gives us a real-time
readout of the non-viable, or non-living, particles in the air. Any particles will
cross the laser beam and be counted. Let's also run the active air sampler to see how many viable
or living particles we have in the air. An active air sampler draws in a specific volume of air - in
this case one cubic foot. The air passes across a culture medium much like the TSA plates we used
earlier. Any viable particles will stick to the media and begin growing once in the incubator.
Let's look at the laser particle counter results from our lab. For every cubic foot of air we
have over 108 000 point-3 sized particles and 8700 point-5 micron sized particles.
Record these results in your lab notebook. Remove the plate from the active air sampler.
Label it and include the word 'static,' and incubate it upside down with the others.
Why did we write static on the last plate? It's because next we're going to have a little fun.
Reset the air sampler in the same position, but this time let's really amp up the human
shedding grossness. Cassi here is going to do some jumping jacks...and
some hand clapping...and some whatever that is! Let's look at the real-time results of our
non-viable particle counts. Wow! All that movement and now we have little pieces of Cassi in the air.
Our 0.3 micron particle count doubled to 228 000 and our 0.5 micron particle count is almost
10 times higher - over a hundred thousand! Remove the plate from the active air sampler and label it
with the word 'active' so we'll know that this is the one from when Cassi was moving around
and getting down. And it goes in the incubator with the others . And now we wait two days,
but through the power of video editing it's time to see our results.
Here's the plate from Cassi's forehead. Take a look at the colonies. There are at least three
different sizes shapes and colors present. Some are umbrella-shaped, some are flat,
and some are orange in color. Each type represents a different organism. Scientists can use these
characteristics to help identify what the organism is. Here's Cassi's finger plate. Again we see
there are at least three different sizes, shapes, and colors present. They're most likely the same
organisms found on her forehead. Many people carry similar organisms as part of their natural flora.
Here's the RODAC plate we use to test the lab workbench. I count about 25 colony forming units,
and I see at least three different sizes, shapes, and colors present. And finally, here are two
plates from the active air sampler. The plate on the left is the static one, and the one on
the right is from when Cassi was moving around. There are five colonies on the static plate,
but over 30 on the active...so almost six times as many colonies are growing on the active plate!
It's true that we are the biggest source of contamination in manufacturing facilities,
but by limiting our movement, wearing the right PPE,
and sterilizing our equipment we can effectively monitor the environment, ourselves, our surfaces,
and the air to make sure our products are free from contamination. Thanks for watching.
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