Nakamura conditions are helpful in demonstrating the presence of the lysozyme substrate in Gram-negative bacteria because: (1) the low pH (3.5) pretreatment uncovers or releases the substrate from a "bound" state within the cell wall for lysozyme digestion; (2) the addition of alkali (to pH 10.0 or above) allows for increased hydration and dispersion of the cell proteins once the lysozyme substrate has been removed. Increased hydration and dispersion alter the index of refraction of bacterial suspensions so that it is near the index of water, and clearing of the suspensions results. Irrespective of the acids and/or alkalies used, little difference was noted in their effect on clearing. The need for caution in attributing lack of clearing in bacterial suspensions to inactivation or inhibition of autolytic enzyme systems is discussed.