In this video, we demonstrate the Congo red staining method to visualize cellulose deposits in Arabidopsis thaliana stem sections.
Protocol
1. Congo Red Staining
Dissolve 0.5 g congo red in 100 ml of distilled water to prepare a 0.5% congo red solution.
Transfer stem sections to a 2.0 ml microcentrifuge tube. Add 1 ml of the 0.5% congo red solution to the tube. Gently pipette the 0.5% congo red solution up and down without disturbing the sections. NOTE: Be careful not to pipette the sections into the pipette tip as this may damage the sections.
Incubate at room temperature for 10 min and repeat the pipetting. Follow with another 3 min of incubation at room temperature.
Use a 1 ml pipette to draw out 700 µl of 0.5% congo red solution. Add 700 µl of distilled water to rinse out the congo red solution. Repeat the wash 3-4x until the washing solution is clear.
Use a 1 ml pipette with its tip cut in such a way that the sections can be pipetted out easily without damage. Gently pipette sections into the tip and onto a microscope slide and cover them with coverslip. Observe the samples on the microscope slide under blue-light excitation using a filter with a bandpass of 560/40. NOTE: Do not store the sections in water for long prior to the microscopic analysis, as the water will wash out the congo red in 10-30 min.
Disclosures
The authors have nothing to disclose.
Materials
Congo Red
Sigma
C6277
Disodium 3,3'-[[1,1'-biphenyl]-4,4'-diylbis(azo)]bis(4-aminonaphthalene 1-sulphonate) [CAS Number 573-58-0]
Microcentrifuge Tubes (0.6 ml)
Axygen Scientific
MCT-060-C
Camera with CCD chip with no mechanical shutter
Hamamatsu
C4742-95
High speed color camera
QImaging
MicroPublisher 5.0 RTV
Camera software
Molecular Devices
MetaMorph version 7.7.0.0
Imagining anaylsis
Adobe
Photoshop CS4
Micro Cover Glasses, Square, No. 1
VWR
48366-067
22 x 22 mm (7/8 x 7/8")-Cover glasses are corrosion-resistant and uniformly thick and flat. No. 1 thickness is 0.13 to 0.17 mm.
Frosted Micro Slides, 1 mm
VWR
48312-003
75 x 25 mm – 1 mm
TX2 Filter cube
Leica
11513851/11513885
Filter used for Congo red analysis with a band-pass of 560/40.