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Running New Samples through the uFCM! (Week 4)

This week I continued working with LabVIEW programming. I added more peak detectors with different threshold values. This way, I can program it to subtract between the different thresholds to get a more accurate count of the number of particles. As the program becomes more sophisticated, it will essentially replace the need to do any analyzing in excel. I also got the chance to run new samples through the uFCM. The 5 um and 20 um beads arrived and I made concentrations with 10 drops of bead stock in 40 ml of deionized water for each bead size. This was the first time we hooked up the uFCM since May and there was a problem. The fittings around the tubing were leaking onto the flow cell. Thank goodness I noticed. The machine had to be taken apart to fix the leaks and clean up the water that had filled inside the cavity. It is a very fragile instrument and has a small work area, but it got fixed and was good to go. I ran the 5 um beads, but the concentration was too high, so I decreased it to 5 drops in 40 ml deionized water. The 20 um bead concentration was borderline—it might need to be increased. The 20 um beads settle pretty quickly because they are relatively big and we didn’t have a good system of keeping the sample stirred while it was connected to the uFCM. The settings in LabVIEW SignalExpress were also increased so that it will process the signal at a frequency 10,000 measurements per second instead of 1,000 measurements per second. The initial data was indicating that the frequency wasn’t high enough due to the “double peaked” events. By increasing the sampling rate, I hope to see all single peaks to where the instrument is picking up every particle. The samples were also ran through the FlowCAM.
Once the samples ran through the uFCM, I exported the new data to excel. With the increased frequency, now there are over a million data points that are being exported per sample. That is a lot of data! Also, for the first couple of runs, I used a normal pump, but it pumps at an irregular rate, and it would be nice to have a constant flow rate so that you don’t see that input in the signal (the signal looks a bit choppy). I tried using a syringe pump for the next couple of runs. You put the sample in a syringe and the machine that it is connected to pushes on the syringe to give a steady output flow rate. The problem with this is, again, not being able to stir it constantly or keep it stirred enough.
On Wednesday, the interns had another brown bag seminar by Paul Tratnyek—“Ethical Issues in Basic Research.” Some of the situations that were presented were really hard to decide what path you would choose if you were faced with that situation. It gave us insight on what to be aware of and what to look out for.
On Friday, all of the interns gave a 5 minute presentation deemed their “midterm presentation.” We got to hear everyone’s project for the summer and what they have been up to with their time at CMOP so far.
Last, but not least: On Saturday, Ethan VanMatre took some of the interns on an “adventure trip.” We hiked part of Mt. Hood. It was about a 7.5 mile round trip and we got up to about 6000 ft of elevation (we hiked about 2200 ft of elevation). It was a tough hike for me, but it was fun. We also went to Oneanta Waterfall. We had to climb over logs and go through water that was waist high in order just to see the waterfall. It was a long day, but definitely worth it.