Fluorescent diagnosis was first proposed in the early XX century and has been used in neurosurgery for about 15 years. The method relies on selective accumulation of strongly fluorescent protoporphyrin IX in tumor cells. Over the past years, the method of intraoperative fluorescence diagnosis has occupied its niche in many neurosurgical clinics around the world and is now used for fast intraoperative diagnosis in brain tumor surgery. However, the efficiency of fluorescent intraoperative diagnosis using 5-aminolevulinic acid is 80-90% and 58.8% for surgery of Grade III-IV and I-II gliomas, respectively. One of the methods to improve the efficiency of fluorescent diagnosis is to use vector systems for delivering fluorescent drugs into the tumor. This paper reports the results of an experimental study of systems for delivering fluorescent agents (protoporphyrin IX, Alexa 488, Alexa 660) using connexin-43 antibodies in rats with transplanted C6 glioma.