We have developed a biochip for the analysis of candidate genes for schizophrenia. Using this biochip, allele and genotype frequencies for the polymorphisms of HTR2A, BDNF and SLC6A4 genes in 198 patients with schizophrenia and 192 healthy individuals have been obtained. The allele T of the HTR2A polymorphism rs6314 was identified as protective against the development of paranoid schizophrenia (p=0,014). An analysis of gene-gene interactions using the Multifactor-Dimensionality Reduction (MDR) algorithm has shown a statistically significant association of combined genotypes rs6311 G/-, rs6313 C/-, rs6314 C/C, rs7997012 G/- with the disease (p=0.019). Also it has been shown that the G/G genotype of the polymorphism rs6311 (p=0.013) and the C/C genotype of the polymorphism rs6313 (p=0.008) in the HTR2A gene are associated with the suicide attempt in schizophrenic patients. Correspondingly, an A allele, А/- genotypes of the polymorphism rs6311 G>A and a T allele, T/- genotypes of the polymorphism rs6313 C>T were found to be less frequent in schizophrenic patients with a history of suicide attempt than in schizophrenic patients without a history of suicide attempt, thus suggesting their protective role in the development of suicidal behavior. The results confirm the hypothesis that the HTR2A plays an important role in the etiology of schizophrenia and suicidal behavior.