I am using 6-mercapto-1-hexanol (MCH) as part of the immobilization procedure for forming a self-assembled DNA monolayer on a gold surface (see the first figure of this paper for a good visual representation). Most protocols I see online and in the literature say to use 1 mM aqueous MCH. For example, this paper says "...mercaptohexanol (MCH) was co-adsorbed onto the DNA-modified gold electrodes by exposing the electrodes to a Tris buffer solution (10 mM Tris, 50 mM NaCl, pH ) 7.3) containing 1 mM MCH for 1 h", and this paper says "The slides were also exposed to a 1.0 mM aqueous solution of 6-mercapto-1-hexanol (MCH) for 1 hr".
However, I am struggling to make this working dilution. As far as I know, MCH always comes as a liquid, so I tried first making a stock 10 mM solution by mixing 1 mg of MCH liquid with 745 µL of water. The MCH appeared to be immiscible in water, however, forming distinct droplets in the water that rise to the top without mixing.
How do I make a working or stock dilution of MCH in water that isn't biphasic?