Oils used in microbatch crystallization do not remove a detergent from the drops they cover

In microbatch crystallizations, a small volume of protein solution is placed in contact with a large volume of oil. Detergents present in the water phase may be expected to migrate into the oil phase, which could have effects on the protein in solution. A new method is described in which detergent partitioning into the oil can be checked. The accuracy of this method is sufficiently high to estimate even very low partitioning coefficients. The measurements indicate that in the case of dodecyl maltoside, no significant loss of detergent will occur.