Biochemical Test Notes | Page 2 of 6

Acetate Utilization Test- Principle, Procedure, Results, Uses

October 4, 2020 by Anupama Sapkota

Acetate Utilization Test- Principle, Procedure and Result Interpretation

What is Acetate Utilization Test? The acetate utilization test is one of the biochemical tests performed for the identification of aerobic organisms by evaluating their ability to utilize acetate present in the growth media. The principle of the acetate utilization test is based on the ability of an organism to utilize acetate as a sole source of carbon. This test …

Acetamide Utilization Test- Principle, Procedure, Results, Uses

October 4, 2020 by Anupama Sapkota

Acetamide Utilization Test- Principle, Procedure and Expected Results

What is Acetamide Utilization Test? The Acetamide utilization test is one of the many biochemical tests performed for the identification of aerobic organisms. This test is based on the utilization of acetamide by the organism via the process of deamidation. The deamidation process occurs in the presence of acylamidase enzyme. An Acetamide utilization test is performed for the distinction between …

Biuret Test for Protein

May 5, 2020 by Sagar Aryal

What does Biuret test for? Proteins are the complex compound formed by thousands of amino acids. Amino acids are amphoteric electrolytes having carboxyl and amino groups that act like acid and base. It has one positive charge and one negative charge, hence these ions are electrically neutral and do not migrate in the electric field. The two amino acids are …

Carbohydrate Fermentation Test | Sugar Fermentation Test

April 27, 2020 by Sagar Aryal

Introduction Carbohydrates are organic molecules that comprise carbon, hydrogen, and oxygen in the ratio (CH2O)n. There are three types of carbohydrates based on their structure and number of carbon atoms present, they are monosaccharides (simple sugar containing 3-7 carbon atoms), disaccharides (comprising of two monosaccharides linked together by the glycosidic bond), polysaccharides (containing eight or more monosaccharide molecules). The energy …

Pyruvate Broth Test

January 3, 2020December 17, 2019 by Sagar Aryal

Pyruvate Broth Test Objectives To determine the ability of an organism to utilize pyruvate. It aids in the differentiation between Enterococcus faecalis and Enterococcus faecium. Principle In the identification of microorganisms, the widely used method is the ability of bacteria to form organic compounds by metabolizing certain carbohydrates and related compounds. Pyruvate broth is a carbohydrate-free, nutrient-limited medium. Pyruvate Broth contains …

Leucine Amino Peptidase (LAP) Test

January 14, 2020December 16, 2019 by Sagar Aryal

Leucine Amino Peptidase (LAP) Test Objective To detect the presence of the enzyme leucine aminopeptidase for the preliminary characterization of catalase-negative, gram-positive cocci, especially non-beta-hemolytic cocci. Principle of Leucine Amino Peptidase (LAP) Test Leucine aminopeptidase (LAP) test is a rapid test for the detection of enzyme leucine aminopeptidase. In general, Streptococcus pneumoniae and Streptococcus pyogenes, Pediococcus, Lactococcus, and Enterococcus sps …

Sulfur Reduction Test

January 1, 2020December 13, 2019 by Sagar Aryal

Objectives To determine the ability of the organism to reduce sulfur for the production of hydrogen sulfide. To differentiate members of Enterobacteriaceae, especially the sulfur-reducing Salmonella and Proteus from the non-reducing Morganella morganii and Providencia rettgeri. Principle The Sulfur Reduction Test is performed using the SIM medium. SIM medium also tests for indole production and motility. It is a semi-solid …

Salt Tolerance Test

January 14, 2020November 28, 2019 by Sagar Aryal

Salt Tolerance Test Objectives To determine the ability of an organism to grow in high concentrations of salt. It is used for the differentiation of Enterococci from Non-Enterococci. Principle Salt acts as a selective agent and interferes with membrane permeability and osmotic equilibrium. The salt tolerance medium is a selective and differential medium in which salt-tolerant organisms will produce heavy …

Kligler Iron Agar Test

January 5, 2020November 25, 2019 by Sagar Aryal

Kligler Iron Agar Test Objective To differentiate the enteric gram-negative bacilli based on the production of hydrogen sulfide and fermentation of dextrose and lactose. Principle Kligler Iron Agar (KIA) test is used in differentiating certain members of the Enterobacteriaceae by demonstrating hydrogen sulfide production and the fermentation of dextrose and lactose. Kligler agar used for the test comprises of casein …

Potassium hydroxide (KOH) test

January 10, 2020May 15, 2019 by Sagar Aryal

Potassium hydroxide (KOH) test Objective To visualize the fungal element in the clinical specimens. To examine skin scrapings or flakes and hair for the presence of hyphae and arthroconidia in suspected dermatophyte infections. Principle Potassium hydroxide (KOH) can be used on clinical specimens to clear cellular material and for better visualization of fungal elements. KOH preparation is a commonly used …