Midori Green DNA loading buffer (LBx2wMidori)
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 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 DNA loading buffer
- 80 µL Midori-green x250 dilution
- 200.0 µL Total
Alternatively
- 200 DNA loading buffer
- 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.