Updated Rhodamine Dilution
I fixed the graph for the serial dilution of Rhodamine that I did last week and removed all absorbency values that were greater than 1.08 AU. The graph looks much more linear now with an R^2 value of .9517
Similar Posts
Pore formation theory
In this post, I will present my thoughts on the possible mechanisms of pore formation based on our most recent observations with the substrate bias experiments. As a precursor, I will discuss silicon crystallization since it is intimately related to the pore formation process. I will try to show that pore nucleation is driven by…
Development of microvasculature mimetic device
From last few months, I am working on the development of a co-culturing system that can work as an in vitro mimetic of the human vasculature. The idea is to make a device capable of co-culturing, real time imaging, equipped with fluidics for testing different assays as well as to grow cells under shear. TEER measurement…
Air-blood barrier #1
Our collaboration with Alison Elder, et al. in the Dept. of Environmental Medicine has led us to talk about developing a co-culture model of the air-blood barrier. This barrier is ‘located’ at the alveolar sacs in the lungs, where lung epithelial cells in the alveolar space are exposed to air. These epithelial cells are separated…
Sham Dialysis Study
We performed four hours of sham dialysis, using two non-porous nitride membranes. The set-up is described in an earlier post. Blood samples were taken when the animal was received, after one week of the adenine containing diet, then at 1 hour intervals during the dialysis. The data shows that the urea level, which was increased over…
EQ! (Permeability)
SepCon EQ reaches Equilibrium in 2 1/2 hours!w310 (no pinholes)1x PBS (no protein)2 hours @ 1000rpm (3.3psi) -> 103 uL passage (56 uL/(min-cm2-psi) )2 1/2 hours @ 1500 rpm (5 psi) -> 204 uL passage (>74 uL/(min-cm2-psi) ) In the second case, the sample visibly reached what looked like equilibrium. It was not quite exact,…
Question about observation through the plastic substrate of the new diffusion chamber
ByJimAttached are the photos taken under DIC and Rhodamine channels, using the new diffusion chamber. I can clearly observe Rhodamine pass to the lower hole of the chamber, under the Rhodamine channel by eye ball. But from what I got using the Matlab software, it looks weird because both DIC and Rhodamine photos look very…
5 Comments
Comments are closed.
What is the absorbance wavelength you are measuring?
The wavelength is measured at 530nm. I checked online and it said that the maximum absobtion of rhodamine is about 530nm.
This looks OK, but I’m still surprised that the data points are not tighter to the line (lower variance). This is close to an ideal system, so I would suggest trying to perfect your technique to get this rock-solid before advancing to more complicated experiments. If you try to measure the same sample multiple times, does the value jump up/down around the line? If so, maybe an averaging is needed?
If you think this is good enough for your purposes, that’s fine too, but you want to make sure that this measurement error is not a significant contributor to the overall experimental error. You should also consider the range of absorbance values that you will typically be using, and confirm accuracy in that regime.
I ran two measurements for each sample and then averaged the two measurements. I’ll run the experiment again on Monday and see if I can get a better fit.
How close were the two measurements for each sample? If each set of two is tight, then the variability is not in the measurement, but the prep. Once you isolate the source of variability, you will probably be able to get nice looking data with a few tweaks of procedure. Even if the variability is outside of your control, it’s still important to understand it for experimental design.