Oct 19, 2021

Public workspaceSDS-PAGE gel electrophoresis V.4

  • 1University of Illinois at Urbana-Champaign;
  • 2Realizing Increased Photosynthetic Efficiency (RIPE)
  • GEGC lab UIUC
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Protocol CitationSteven J Burgess, Lynn Doran 2021. SDS-PAGE gel electrophoresis. protocols.io https://dx.doi.org/10.17504/protocols.io.by6zpzf6Version created by Lynn Doran
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License,  which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it’s working
Created: October 18, 2021
Last Modified: July 11, 2023
Protocol Integer ID: 54201
Funders Acknowledgements:
Realizing Increased Photosynthetic Efficiency (RIPE) that is funded by the Bill & Melinda Gates Foundation, Foundation for Food and Agriculture Research, and the U.K. Foreign, Commonwealth & Development Office
Grant ID: OPP1172157
Abstract
SDS-PAGE gel electrophoresis protocol for analyzing samples from plant leaf tissue via immunofluorescence. In this protocol no Coomassie blue is added to samples, the reason is that this interferes with the fluorescent signal during immunoblot. Instead, samples have already been prepared in Laemmli buffer (minus coomassie, protein extraction procedure), the leading edge of samples can be visualized due to the presence of chlorophyll.

Note
- When using 15 well, 0.75 mm comb, try to limit the volume loaded to 10 μL to minimize the risk of spillover of protein between wells.
- Ensure that accurate volume is pipetted by removing sample stuck to the outside of the pipette tip by wiping the tip on the rim of the sample tube to remove any residual liquid.


Literature:
Materials
  • 4–20% Mini-PROTEAN® TGX™ Precast Protein Gels, 15-well, 15 µl (Bio-Rad Laboratories; 4561096)
  • Opening lever (Bio-Rad Laboratories; 456-0000)
  • Chameleon™ Duo Pre-stained Protein Ladder (LI-COR Biosciences; NC0738562)
  • Mini-PROTEAN® Tetra Vertical Electrophoresis Cell, 4-gel (Bio-Rad Laboratories; 1658004)
  • 10x Tris/Glycine/SDS (Bio-Rad Laboratories; 1610732)
  • Fisherbrand™ Gel-Loading Tips, 1-200 µL (Fisher Scientific; 02-707-181)
  • ImperialTM Protein Stain (Thermo Scientific; 24615)s
  • Bio-Rad Gel-Doc Imager (optional)

Before start

Previously extracted and quantified protein samples can be stored at Temperature-20 °C .
Prepare gel tank and buffers
Prepare gel tank and buffers
  • Create a 1X working dilution of Tris/Glycine/SDS buffer (~Amount1 L is required per gel tank) by diluting 10X stock 1:10 with distilled H2O.

Carefully remove the comb from the precast gel and the tape across the bottom.
Assemble the Mini-PROTEAN electrophoresis cell and fill the inner chamber with buffer and the outer chamber up to the recommended mark
Note
The volume varies depending on whether running 2 or 4 gels, the level is marked on the tank.

Wash the wells with running buffer by pipetting up and down
Note
This is done to remove residual acrylamide that may have collected in wells

Prepare Samples
Prepare Samples
10m
10m
In fresh microcentrifuge tubes, create a dilution of each sample using 1x PEB to a concentration of 3 μg /uL of total soluble protein.
Note
Recommended final volume ~Amount100 µL (this will allow for 10 samples) but will depend on the application.


Note
Heating previously frozen protein extracted samples at 5Temperature50 °C for Duration00:05:00 can help resolubilization of SDS in protein extraction buffer prior to making dilutions.


Briefly vortex the sample to shear any DNA contamination.
Load Amount3 µL of Chameleon™ Duo Pre-stained Protein Ladder to the first well.

Load Amount10 µL of each sample (30 µg of total soluble protein) per lane.

Running Gel
Running Gel
10m
10m
Run precast gels at 200 V for ~Duration00:30:00 or until the samples have reached the end of the gel. In some applications it may be advantageous to run the chlorophyll off the end of the gel to improve fluorescence and signal on the protein of interest.

Equipment
Mini-PROTEAN Tetra Cell
NAME
Gel Electrophoresis Tank
TYPE
Bio-rad Laboratories
BRAND
1658005EDU
SKU
LINK

Note
For self-made gels, run at 80-120 V.

30m
Carefully open precast gel case using an opening lever, by inserting where the black arrows indicate on the gel case.
Remove stacking gel with a blade
Proceed either directly to Protein Transfer using Bio-rad TransBlot Turbo or Total Protein Staining.