Diagnosis of infectious agents in histology involves various steps: 1. Histopathological Examination: Initial examination of tissue sections using H&E (Hematoxylin and Eosin) staining to identify general tissue architecture and inflammation. 2. Special Stains: Use of specific stains like Gram, Ziehl-Neelsen, PAS, and GMS to highlight particular organisms. 3. Immunohistochemistry: Application of antibodies specific to infectious agents to detect their presence. 4. Molecular Techniques: Methods like PCR and in situ hybridization to identify genetic material of the infectious agents.