To create a 1:2 dilution, you need 1 part of the protein solution and 2 parts of the diluent (in this case, water). This means that for every 1 part of protein solution, there are 2 parts of water.
Since you want a total volume of 100 ml, you can think of the dilution as having a total of 1 + 2 = 3 parts.
To find the volume of each part, divide the total volume by the number of parts:
100 ml ÷ 3 = 33.33 ml (approximately)
Now, since you need 1 part of protein solution, you will take:
Protein solution = 33.33 ml
And for the water, since it’s 2 parts:
Water = 2 x 33.33 ml = 66.67 ml
In summary, to make 100 ml of a 1:2 dilution of a protein solution, you would use approximately 33.33 ml of the protein solution and 66.67 ml of water.