Methods for treating a bacterial infection in a tissue sample are described. Tissue samples that are harvested from a patient may be infected with bacteria. A rhodamine compound is mixed with the infected tissue sample to form a mixture. The mixture is then exposed to radiant energy to inhibit or kill the bacteria. The exposed mixture is then transplanted into the patient. Examples of rhodamine compounds include 2′-(6-dimethylamino-3-dimethylimino-3H-xanthen-9-yl) 4′,5′-dichloro-benzoic acid methyl ester hydrochloride; 4,5-dibromorhodamine 110 2-(2-methoxy ethoxy)ethyl ester hydrobromide; acetate salt of 2,7-dibromorhodamine B hexyl ester; acetate salt of 2,7-dibromorhodamine B methyl ester; 4,5-dibromorhodamine 6G hydrobromide; rhodamine B 3-bromopropyl; acetate salt 2,7-dibromo-4′-carboxytetramethylrosamine methyl ester; 4-bromo-5-phenyl rhodamine B methyl ester chloride; 2,7-dibromo-4,5-dimethyl rhodamine B methyl ester bromide; 2-bromo-7-ethynyl rhodamine B methyl ester bromide; and 4,5-dibromo-2,7-di-n-butyl rhodamine B methyl ester bromide.