Bacteriology

Antibiotic Sensitivity disc are used to determine the effectivness of an antibotic against a microorganism as a guide to antibiotic therapy. The disc consist of a specific concentration of an antibotic in mcg which is tested against a microorganism of a standard density, swabbed uniformly on an appropriate media following overnight incubation. Chloramphenicol is impregnated on a filter paper disc of specified concentration. Both sides of the disc are printed with symbol C and concentration 30 mcg for easy identification.

Reticulocytes are juvenile red cells, which contain remnants of basophilic ribonucleoproteins. This material reacts with brilliant cresyl blue to form a bluish black precipitate of granules or filaments.

both the dyes.

Decolourizer is one reagent used in this process to provide the color differentiation. A decolourizing solution is used to remove the Primary Stain from cells which bind it weakly and then the counterstain (like safranin) is used to provide a colour contrast in those cells that are decolourized.

Lugol's iodine is used as staining solution to detect intestinal protozoa and helminth ova or larvae. It is rapid contrast dye that is added to direct wet mounts of fecal material to aid in differentiating parasitic cysts from host white blood cells. Lugol's iodine stain the protozoan nuclei and intracytoplasmic organelles brown making them easier to identify.