I try to find an equation for optimizing voltage and time in transferring proteins.
Dear Phuttiphat,
you might find the specifications you want here:
https://www.thermofisher.com/gr/en/home/life-science/protein-biology/protein-biology-learning-center/protein-biology-resource-library/pierce-protein-methods/western-blot-transfer-methods.html
Kind regards
Hello Phuttiphat Manarangtaweekul
During blotting, the distance that must be travelled (gel thickness) between electrodes is much less than during separation, so lower voltage and lower field strength (volts/distance) are needed. On the other hand, the cross sectional area of current flow is much greater, so higher current is required.
Blotting power requirements depend on field strength (electrode size) and conductivity of transfer buffer. The higher these are, the higher the current requirement will be, although throughout the run, current drops as the ions in the buffer polarize. Therefore it is important to ensure that the power supply being used can accommodate the initial high current requirements. It is also important to have a well rectified power supply which ensures power will flow unidirectionally.
If the voltage is too low and transfer time too short, some protein will be left in the gel. If the voltage is too high, smaller proteins may pass through the membrane before they bind. If proteins are left in the gel after blotting under recommended conditions, then increasing the voltage by no more than 5 volts may be helpful. However, note that once SDS has been stripped from protein, longer transfer times or higher voltages will not help. Once bound, most proteins will remain on the membrane even during extended transfers.
The use of 25 V for 1-2 hours will transfer small proteins fairly effectively (up to about 50 kDa), and transferring at 30 V overnight (16 h), or even using a lower voltage such as 15 V will effectively transfer all proteins, regardless of the size. The main risk involved with the long transfer is transferring the small proteins through the membrane rather than on to it.
You could also refer to the paper attached below which may help in answering your question.
Article Voltage profile generation for simultaneous multi-protein de...
Best.
Dear Antonis Tsintarakis and Malcolm Nobre,
Thank you very much for your contribution
Sincerely,
Phuttiphat
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