@Will-Dickson Hi, trying to do the same thing. Replaced the R8 with a 22 Ohm resistor. Having difficulty finding the changes necessary in the firmware files though. Recon you point me to lines which need changing?
First, the output voltages are set at discrete time points via the testTimer which run by default at 5kHz. To make a reasonable approximation of a sine wave you will probably want enough points - maybe 50 or so. So you could probably output reasonable approximations of sinusoids voltages up to frequencies of about 100Hz.
Second, the data is not sent back to the PC (or other device connected via UART) at every update of the testTimer. Rather it is sent at a lower sub-sampled rate set by the sample rate (or actually sample period in the firmware). The maximum value for the sample frequency is 1000Hz. You will need sufficient number of sample points at which to measure the current you get in response to the sine wave output. So maybe 20 or 30 or 50 ... the exact number depends on your needs. Lets say that 20 is sufficient. Then this further reduces the maximum sinusoid frequency to 50Hz (1000/20).
Third you will need to take into account the bandwidth of the current measurement range you are using e.g. +/- 1uA, +/-10uA, +/-100uA, +/-1000uA. Each of these channels will lowpass filter the measure signal to some extent based on the resistor capacitor combination used in the feedback network of the transimpedance amplifier. The more sensitive channels will have lower cutoff frequencies. The +/-1000uA and +/-100uA channels have pretty high cut off frequencies such that it won't be an issue. However, the +/-10 uA and +/- 1uA ranges have cutoff frequencies of approximately 47Hz and 4.7Hz respectively. So if you are using these channels this will limit the bandwidth of your measurements somewhat or at least you should be aware of the possible attenuation of the measurements at higher frequencies.
That is a good question ! We haven't tried using glass instead of acrylic for our transilluminator. However, you could certainly put your gel onto a small glass plate over the clear acrylic when you are cutting gels to protect the acrylic. You can look for small glass plates online e.g. McMaster-Carr and other stores. We will also have a look at finding some glass plates to recommend with our different transilluminator sizes.
If you would like a replacement for your scratched clear acrylic surface, we can send you one, no problem, just let us know and we will happily help with that !
Hi...i am a new user here. I don't have much experience but as per my observation the control amplifier will still be running trying to control the voltage between the reference and working electrode, so can disconnect the counter electrode.
The Rodeostat has voltage ranges of +/-1, +/-2 , +/-5 and +/-10V. So it can achieve the voltage you want without modifications.
The standard current ranges are +/-1, +/-10, +/-100 and +/-1000 uA. Which are a bit lower than you are looking for. We have made modified versions with increased current range. The limit on this was about 24mA (24000uA). There is a topic discussing the modifications here Increasing current ranges to detect mA
Thank you for your question. At this time we don't conduct teacher training workshops. However, we are always available to help and answer questions from individuals regarding using the colorimeter or any of our other products.
Hi, I read through your message and I'm wondering whether this is a general question about gel electrophoresis or whether you are having trouble with your electrophoresis equipment. Are you using our IO Rodeo gel box and electrophoresis power supply ? It doesn't seem from your message to be an equipment problem, but more a problem with a new loading dye that you are using ? If that is the case, you might be better off asking the manufacturer of the loading dye whether you should expect to see you DNA sample behave differently in their buffer. I'm sorry I haven't used the GoTaq loading dye.
I hope that helps. Good luck with your PCR experiments and let us know if you have any specific questions about our electrophoresis equipment.
Thank you for your kind words about our work and for reaching out ! We will definitely take a look at the openhardware.science website, thanks. Your work sounds very cool, and we would love to chat further. We sent you a message on here so look for that and hopefully we can connect and chat soon !
You could use the linear sweep voltammetry (LSV) test in the cheapstat firmware to do anodic stripping voltammetry. The settling time parameter can be used to set the time for your preconcentration step.
There is also a squarewave voltammetry (SWV) test in the firmware. This would almost do what you want for squarewave anodic stripping voltammetry. Unfortunately there doesn't seem to any period at the beginning of the trial which could be used for your preconcentration step. However, I think it would be pretty easy to modify the firmware to add this. The SWV test in implemented in the SWV_test function in cheapstat.c. For an example of how this delay at the start of the trial could be implemented you could look at the LSV_test function which implements the linear sweep voltammetry.