Rotating cells

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Revision as of 20:39, 16 December 2021 by Morteph@uio.no (talk | contribs) (i added a short summary of the first experimetn done with yeast cells.)

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Electrorotation setup. This circuit contains two D-flipflops and provides 4 output voltages that have the same signal frequency and amplitude but are phaseshifted by 90° from one to another.

This is the main page of the rotating cells/electrorotation project.

Time line

-16.03.21 First online meeting within the electrorotation group, in which we introduced each other and talked about our backgrounds and research interests.

-24.03.21 Online seminar about electrorotation and ponderomotive forces in general given by Prof. Jan Gimsa from the University of Rostock.

-29.03.21 Second online meeting within the electrorotation group before Easter break where we discussed our plan of action. First thing on the to-do list is to develop instrumentation that enables electrorotation.

-08.04.21 Some members of the team got started on develop the instrumentation. The prototype has been developed and checked on a breadboard. The results were not perfect and needs more work.

Students are working on the instrumentation..jpg

-13.04.21/14.04.21 Third online meeting within the electrorotation group. The team has decided to test out the instrumentation for electrorotation using yeast cells in order to see whether we will be able to rotate the cells. Team members have also discussed potential project ideas, where some consisted of working with cancer cells, specifically on tumour heterogeneity or researching their polarity, which would be possible to do using electrorotation. Some other ideas consisted of looking into a genetic illness called ALD, which stands for Adrenoleukodystrophy. In order to decide on the research title, the team has decided to have a meeting with a few experts in the nearby future to discuss the feasibility of these ideas.

The prototype has also been fixed - the device is now able to produce a signal with correct phase shifts using a D flip flop.

----- Summer Break -----

-13.10.21 Electrorotation team had its first official meeting with the new and old members of the group. We have discussed the future of our project, particularly our ideas regarding ADL and inspecting it using electrorotation. The biologists of the group drafted a research proposal that we will be making come to life. To do so, we agreed on drafting an email to the Hybrid Technology Hub (HTH) to get help with the cell lines and other biological methods that we will need in order to "induce" ALD in our cells.

-26.10.21 Meeting with a post.doc from HTL to discuss cell lines. Exchanged ideas, as well as past research papers with focus on ALD. Potentially getting cell lines from another research group, however, this is of sensitive matter and should be done within the framework of an MTA allowing them to be associated with our work on these cells. Hence, we will be joining future publications, which our group is very excited about.

Project progression

First semester: 03.21 - 06.21 :

- We need to start to develop the instrumentation that enables electrorotation. We got already the electrodes for it (see Fig. 1) and just need to add some small electrical circuit that enables the application of an alternating electrical field.

-The development of the instrumentation has been started. Members of the team followed Anders Jansen's master thesis section Method and materials, specifically Figure 3.6, in order to connect the dual D-type Flip Flop. The D flip flop used by us was different to the one used by Anders, so we had to follow the data sheet of our d flip flop in order to install it correctly, while still following Jansen's circuit diagram. D flip flop used by us was Toshiba TC74HC74AP.

Second semester: 08.21 - 12.21 :

- Working on acquiring cell lines from HTH in collaboration with external research groups in the framework of MTA. Introducing new members to our work and research project.

- Getting some training with the new cells lines to get experience with cell culturing and keeping cells alive. Then, rotating the cells and obtaining rotational spectra.

experiments

test of equipment and principle

To test the electrorotation equipment we replicated the methods and experiment done by Anders Jansen as well we compered dry and wet yeast.

We started by growing the dry yeast to a concentration of 8,8*10^7 cells per ml and the wet yeast to a concentration of 8,6*10^7 cells per ml, we calculated this as follows. 2 grams of dry yeast and 3,25 grams of wet yeast. We then calculate the given density of yeast cells in each yest type, which gives us 8,6*10^10 cells for wet yeast and 8,8*10^9 cells for the dry yeast. We then use the formula C1*V1=C2*V2 formula to calculate the given concentration of cells when we add 49,5 ml of tap water and 2g of sugar to each culture. Each culture was then grown for 30 to 40 minutes giving the cultures depending on how active they appeared to be based on pressure and heat generation.

Cells from each culture where then placed in the electrorotation chamber and the equipment was tested, the equipment functioned as hoped and no difference was found between the cultures.
Fig. 1: Electrodes for the electrorotation project that were provided by Jan Gimsa.

Literature

- Jan Gimsa "A Unified Resistor-Capacitor Model for Impedance, Dielectrophoresis, Electrorotation, and Induced Transmembrane Potential"

https://doi.org/10.1016/S0006-3495(98)77600-3

- Ørjan G. Martinsen et al. "Interface phenomena and dielectric properties of biological tissue"

https://www.mn.uio.no/fysikk/english/research/projects/bioimpedance/publications/papers/encyclop.pdf

- Master thesis Anders Jansen " A feasibility study of electrorotation as an alternative to impedance measurements"

https://www.duo.uio.no/bitstream/handle/10852/65672/1/Masteroppgave---Anders-Jansen.pdf