The invention relates to an enzyme solution, which is used preferably for pre-treating mammalian cells for flow-cytometric detection of light chain restriction of the cells, the enzyme solution comprising at least two proteases, which are proteolytic and also collagenolytic, in a buffer. Preferably, the enzyme solution comprises trypsin, collagenase 4, dispase and astacin. The invention also relates to uses of the enzyme solution and methods for flow-cytometric detection of light chain restriction of cells.