It is time to complete the immunostaining protocol with guidance from Jo-Maree. I must admit that with holidays looming, my note taking was a bit sketchy. I will need to follow up with Jo-Maree to record the correct details of DAPI and Fluorescein Phalloidin stain. This will ensure that I know how to prepare (and order) stocks in the future.
I already prepared a couple of wells at different cell concentrations ready for staining. We had to delay the protocol, so some of the higher concentration wells are likely a bit over-confluent. It will be interesting to see how they look under the fluorescence microscope.
CELL FIXATION: ‘Dirty’ Biolab
Working with 4% PFA in Fume Hood
Prior to imaging, I fixed the cells in 4% PFA:
- Remove culture media (discard in waste container with bleach)
- Wash cells with PBS (discard in waste container with bleach) x 2
- Move cells to fume hood
- Add 4% PFA to each well for 15 – 20min at room temp (in fume hood)
- Remove 4% PFA solution (discard in PFA waste container in fume hood)
- Add PBS (make sure cells are covered or they dry out and produce poor images
IMMUNOSTAINING: At lab bench area
Working at lab bench in the Stroke Group area
- Remove PBS from each well
- Add 1mL 0.3% Triton X-100 (a strong detergent) to permeabilize cells (make cells permeable – this allows the phalloidin stain to enter the cell structure) for 10 min
- Make up DAPI (5mL PBS Tween and 1ul DAPI) and protect from light with aluminium cover
- Remove Triton X-100 and add 1mL DAPI solution to each well and incubate at room temp (with aluminum cover to protect from light) for 5 minutes
- Make up Flouroscein Phalloidin (1mL PBS sand 2μL Flouroscein) and protect from light
- Remove and discard DAPI solution
- Add 1mL PBS 0.1% Tween to each well for 5 min then discard x 3 (i.e. wash with PBS Tween x 3)
- Add Phalloidin stain to each well.
- Incubate at room temp for 1 – 2 hours
- Remove Phalloidin solution
- Wash with PBS Tween x 2
- Add 1mL PBS in each well
- Cover with aluminum foil to protect from light.
- Cells are ready for imaging. They can be stored in the fridge (with aluminium foil cover) until ready.