Trypan blue

[labgnome]

Hi all,
I'm using trypan blue to check viability of yeast (Pichia pastoris) cells. I would like to know after what time do viable cells begin to take up the dye? Any help would be much appreciated

[admin]

Hello labgnome,

trypan blue is pretty fast working usually within 5 minutes you can get results.

Here is a simple trypan blue protocol:

1. Place a suitable volume of a cell suspension (20-200 μL) in appropriate tube
2. Add an equal volume of 0.4% Trypan blue and gently mix, let stand for 5 minutes at room temperature.
3. Place 10 μl of stained cells in a hemocytometer
4. Count the number of viable (unstained) and dead (stained) cells.
5. Calculate the average number of unstained cells in each quadrant, and multiply by 2*10^4 to find cells/ml.
6. The percentage of viable cells is the number of viable cells divided by the number of dead and viable cells.

Hope this helps