Two-beam Michaelson interferometry was used to study concentration gradient layers around gel-grown tetragonal lysozyme crystals. Crystals were grown in gel to depress convection and mimic microgravity. The evolution of the concentration profile near the growing surface, the width of the concentration layer, surface concentration, and concentration gradient were investigated and the correlation of these parameters with lysozyme crystal growth is discussed. The concentration gradient properties of gel-grown crystals were compared to those obtained for solution-grown crystals and were found to be different from their solution-grown counterparts. In particular, concentration gradients were wider and transport rate were slower for gel-grown crystals than for solution counterparts.