Preparation of 6X DNA Loading Dye (Bromophenol blue, xylene cyanol FF and Sucrose) Alternative Method


This method uses 40% sucrose solution instead of sucrose powder. This method is convenient and easy, and does not involve adjustment of volume.


Reagents and solutions
Bromophenol blue
Xylene cyanol FF
40% (w/v) Sucrose solution (sterile)
Deionized / Milli-Q water

Equipment and disposables
15-ml screw-cap graduated polypropylene centrifuge tube
Centrifuge (for 15 ml tube) 
Tube rotator (optional) 
Vortex mixer (optional)


Composition of 6X DNA loading dye 
0.25% (w/v) bromophenol blue
0.25% (w/v) xylene cyanol FF
40% (w/v) sucrose

Composition of 1X DNA loading dye 
0.042% (w/v) bromophenol blue 
0.042% (w/v) xylene cyanol FF
6.67% (w/v) sucrose

Preparation of 10 ml of 6X DNA loading dye containing bromophenol blue, xylene cyanol FF and Sucrose


To prepare 10 ml of 6X DNA loading dye, weigh out 25 mg bromophenol blue and 25 mg xylene cyanol FF. Transfer it to a 15-mL screw-capped graduated tube. Add 10 ml of 40% sucrose solution. Mix vigorously using a vortex mixer or tube rotator to dissolve bromophenol blue and xylene cyanol FF in 40% sucrose solution. 

This method is simple and convenient as it does not involve readjustment of solution volume. There will not be any significant change in the volume of the 40% sucrose solution when you dissolve small amounts of  bromophenol blue and xylene cyanol FF in it.

We recommend using disposable nuclease nuclease-free (DNase- and RNase-free)15 ml screw-capped graduated tubes instead of beaker as all the procedure can be done in a single tube. 

Store the solution in the freezer (-20°C). Solution can be stored at 2 – 8°C for a few weeks.

Sucrose-containing loading dyes are prone to mold-like growth. Avoid keeping it in the refrigerator or room temperature. 

It is recommended to store the solutions in small aliquots (1 ml) at -20°C.

This solution is used for loading DNA samples onto non-denaturing gels.

Follow the table to prepare 6X agarose gel loading dye of various volumes.
Reagents / Volume5 ml10 ml25 ml50 ml100 ml
Bromophenol blue12.5 mg25 mg62.5 mg125 mg250 mg
Xylene cyanol FF12.5 mg25 mg62.5 mg125 mg250 mg
40% Sucrose solution5 ml10 ml25 ml50 ml100 ml


Use Calculator to calculate the amount of different components of 6X DNA loading dye

Volume of the 6X DNA loading dye: ml
ml(Change the volume of the solution)

Amount of Bromophenol Blue: mg

Amount of Xylene Cyanol FF: mg

Amount of 40% Sucrose: ml

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