💡 Staph = Catalase +. Strep = Catalase -. Coagulase + = S. aureus.

💡 E.coli = Green metallic sheen on EMB. Pseudomonas = Blue/green pigment.

💡 HBsAg = active infection. Anti-HBs = immunity. HIV = CD4 T cells.

💡 P. falciparum = most deadly, banana gametocyte.

💡 TB: AFB stain, Mantoux test. Lepromatous = diffuse, multibacillary. Tuberculoid = paucibacillary.

💡 Candida = pseudohyphae. Aspergillus = septate, 45°. Mucor = non-septate, 90°.

💡 Classical pathway = C1q (IgG/IgM). Alternative = C3. MHC I = all nucleated cells.

💡 Live vaccines: BCG, OPV, MMR, Yellow Fever. Cannot give in pregnancy.

💡 Treponema = syphilis (VDRL screening, FTA-ABS confirmatory). Leptospira = Weil's disease.

💡 Autoclave = 121°C, 15 psi, 15 min. Hot air oven = 160°C, 1 hour.