Note: An easy way to do this is fixing the tubes in a metal rack in a pre-heated water bath or in a beaker on a heat plate. Maintain bath level at same level as the liquid in the tubes.
Decant and discard the 8 N NaOH and wash algae 3 x with A. bidest. for at least 5 min.
Add 1% aniline blue (w/v) to freshly prepared Sørensen’s phosphate buffer.
In the following, it is recommended to work under low light intensities (~5 μmol photons m-2 s-1) to prevent degradation of the dye.
Stain algae in 1.5 ml of 1% aniline blue for 1 h (Figure 1D).
Note: Incubate in darkness under gentle shaking.