The drug, 5-aminolevulinic acid (ALA), which leads to intracellular accumulation of fluorescent porphyrins in gliomas will be used under investigation for identification and resection of high and low grade gliomas. Surgery will be done using a modified neurosurgical microscope, with a fluorescent kit that enables switching from the conventional white light to a violet-blue excitation light for visualization during tumor resection. If deemed safe by the neurosurgeon, any area of the resection bed determined to be fluorescence-positive for tumor will be removed with appropriate designation of tissue for histopathological evaluation. After this resection, additional fluorescence images will be obtained and the process repeated until the image is negative for tumor. At all times, the decision to resect will be limited by clinical judgment of safety.