I am having difficulty in cutting thin section of membranes (by razor) even though fractured in LN2 for 10 min. How to make thin sections (any specific size for SEM) of fouled PVDF hollow fiber membranes through freeze-drying or liquid nitrogen fracturing or critical-point CO2 drying to observe surface morphology and cross-section view?
Also want to know Is it necessary to fix the membrane (2.5% glutaraldehyde for 1hr and 1% osmium tetroxide for 1h) and dehydrate in ethanol/ water solution (30 to 90%) prior to biofilm surface and composition analysis by SEM/EDS?
Many thanks,
HARSHAD
I have worked intensively on hollow-fiber membranes and microscopic imaging constituted a major part of my research. I did not use liquid Nitrogen for SEM imaging, I used to place the piece of membrane on the holder and I used to take images directly on the membrane surface. However, I performed countless thin sections on hollow-fiber membranes but for Confocal Laser Scanning Imaging. I used to embed the membrane piece in Jung Tissue Freezing medium, which is conventionally used while performing thin cryosectionning. (This viscous thick reagent is liquid at room temperature and hardens quickly at -20 degree C). Then, I used to cut thin slices of the hollow fiber membrane in transverse direction, into 20 micron thick slices using a Cryostat CM 3050 E (Leica Biosystems), at 20 degree C.
Regarding the fixation step that uses 2.5% glutaraldehyde, I believe it is quite essential be ause it will preserve the structure of the fouling layer on the membrane surface and it will also prevents the breakage of this layer while cutting the membrane into thin slices.
Please feel free to refer to the paper that I published in Water Research.
- Badges
- Science topic
- Similar topics
- Phytochemistry
- Extracts