Midori green is one of many alternatives to EtBr. Midori Green is sold
by Nippon genetics.
This stain is compatible with blue-LED transilluminators which is an advantage to
use if DNA is to be cut out of the gel due to the lower
level of DNA damage.
Dilute the Midori-green advance solution 250x (4 µL in 996 µL water).
This solution can be stored in the fridge or frozen. Store in a light proof
container, light could degrade the dye.
Reciepe for 2x concentrated loading buffer:
- 53.2 µL H2O
- 66.8 µL Loading buffer x 6
- 80 µL Midori-green x250 dilution
- 200.0 µL Total
Alternatively
- 200 Loading buffer x 6
- 1000 µL H2O
- 2 µL Midori green undiluted
This solution can be frozen and thawed several times without loosing efficiency.
If you have many samples, spot a 5 µL drop of the LBx2wMidori buffer on a piece of parafilm for each sample.
Add 5 µL DNA containing sample on top of the loading buffer drop. Add the mixture to the agarose gel, further mixing is
usually not needed.
Adding Midori-green to the loading buffer saves time and chemicals (in particular Midori-Green, which is quite expensive) compared to post staining
or mixing Midori-green in the gel.