1 minute.
Background material may cause confusion.
pH = 9.
Acetone.
Enrichment broth for anaerobic bacteria; Determines aerotolerance – ability to live at a particular level of oxygen.
It is used for the recovery of Legionella and Nocardia, and it is specialized for aerobic organisms and fastidious.
It is used for the recovery of Vibrio species.
Toluidine blue O stain.
Direct clinical examination of stool, vaginal discharge, urine sediment, aspirates.
Determining the cellular composition of a sample in terms of its morphology, gross and microscopic biological activity, and motility.
It acts as a disinfectant and destroys some of the surrounding contaminants.
Lactophenol cotton blue.
It preserves the structure and prevents deformation.
Chitin component.
Assist the attachment of the dye, particularly the primary stain, to the cellular component and make the primary stain more stable by forming a complex.
To inhibit the growth of some bacteria but allow others to grow.
Rapid detection of fungi.
They are positively charged (cation).
Assist the removal of the primary stain if it can be removed.
To allow visualization of metabolic differences between groups or species of bacteria.
Gram stain.
Negatively charged (anion).
Crystal violet or methylene blue.
pH = 7.2-7.4.
Gram-positive and Gram-negative.
It is the functional group of the dye that gives color to the stain.
Safranin red.
Crystal violet.
It gives ionic property to the stain.
Basic.
pH = 3.
Iodine.
Cells that retain the primary stain and those that are being removed by the decolorizing agents.
-10-20°C.
10-40°C.
Safranin red.
40-70°C.
Carbolfuchsin.
70-110°C.
Acid alcohol.
Methylene blue.
Methenamine silver stain.
It is used for the recovery of Bordetella pertussis.
Recovery of bacteria and fungi; Detection of aerobic and facultative anaerobic organisms.
Recovery for fungi; No bacterial growth; addition of antibiotics to allow fungal growth.
Yellow: ferments lactose (e.g., E. coli); Red: ferments carbohydrates (e.g., Shigella); Black: H2S producing bacteria (e.g., Salmonella typhi).
Presence of enzyme producing catalase using H202, typically found in Staphylococcus spp.
Organism can degrade amino acid (trp → indole) using Kovac reagent, producing a cherry red reaction; typically found in E. coli and Vibrio cholera.
Beta hemolysis: complete; Alpha hemolysis: partial (peroxide producing bacteria); Gamma hemolysis: none.
Bacterial susceptibility test medium; Used for antibiotic susceptibility and resistance testing.
Isolating pathogenic fungi, selective for molds, and uses chloramphenicol.
Selective for mycobacteria; Solidified agar.
Production of cytochrome oxidase (Indophenol oxidase), typically found in Pseudomonas and Vibrio cholera (purple color).
Color change by hydrolyzing reaction for urea to ammonia and CO2 production, typically found in Proteus spp. and Morganella morganii.
Selective for gram (-) bacteria; differential for lactose-fermentation.
From RED (neutral or no acid) to PINK (acidic).
It is used for the recovery of E. coli 0517, and it causes complications of Hemolytic Uremic Syndrome; lactose was previously replaced with sorbitol, and it does not ferment sorbitol (NO FERMENTATION=NO COLOR CHANGE).
Absence of the clumping of cells causing coagulation, typically found in Staphylococcus epidermis or Staphylococcus saprophyticus.
Presence of citrate being used as a carbon source by bacteria, leading to a rise in pH, typically found in Klebsiella.
Absence of citrate being used as a carbon source by bacteria, typically found in E. coli.
Lactose fermenters turn PINK (acidic); Nonlactose fermenters do not change color.
Selective for Staphylococci; differential for Staphylococcus aureus.
Selective for Salmonella and Shigella in enteric cultures.
Selective, differential for selected bacteria and yeasts.
Absence of the production of cytochrome oxidase, typically found in E. coli, Klebsiella, and Salmonella (no color change).
Absence of the ability to degrade amino acid using Kovac reagent, typically found in Klebsiella, Salmonella, and Shigella.
It is used for the recovery of Corynebacterium diphtheriae, and it produces gray-black colonies against a red-brown background.
Absence of the enzyme producing catalase, typically found in Streptococcus bacteria.
Selective for mycobacterium; Provides definitive diagnosis.
Production of clumping of cells causing coagulation, typically found in Staphylococcus aureus.
