Medicallabnotes Archives - Page 92 of 120

Optochin Susceptibility Test: Introduction, Principle, Test Requirements, Procedure, Result-Interpretation, and Keynotes

January 13, 2023January 12, 2023 by Medical Lab Notes

Optochin Susceptibility Test Optochin Susceptibility Test uses for presumptive identification of Streptococcus pneumoniae from viridans streptococci. Principle of Optochin Susceptibility Test Ethylhydrocupreine hydrochloride (Optochin), a quinine derivative, selectively inhibits the growth of S. pneumoniae at a very low concentration (5ug/ml). Optochin may also inhibit other viridians streptococci, but only …

CAMP Test: Introduction, Principle, Test Requirements, Procedure, Result-Interpretation,and Keynotes

January 13, 2023January 12, 2023 by Medical Lab Notes

Introduction of CAMP Test The CAMP test uses to identify preemptively Streptococcus agalactiae. It was first described in 1944 by Christie, Atkins, and Munch-Petersen, and the CAMP test is an acronym for their names. Principle of CAMP Test The beta lysin produced by Staphylococcus aureus is sphingomyelinase in nature, …

Acetate Utilization Test: Introduction, Composition, Principle, Test Requirements, Test Procedure, Result and Interpretation, and Keynotes

January 13, 2023January 12, 2023 by Medical Lab Notes

Acetate Utilization Test-Negative (left) and Positive (right side)

Introduction of Acetate Utilization Test Acetate Utilization Test ueses to determine the ability of an organism to use acetate as the sole source of carbon same as in the citrate utilization test for Enterobacteriaceae. It is the recommended assay for the differentiation of Shigella species from Escherichia coli. Composition of …

Corn Meal Agar (CMA): Introduction, Composition, Principle, Test Requirements, Test Procedure, Result-Interpretation, Colony Characteristics, Uses, and Keynotes

January 13, 2023January 6, 2023 by Medical Lab Notes

Colony Morphology of Aspergillus flavus on cornmeal agar (CMA) demonstration

Introduction of Corn Meal Agar (CMA) Corn Meal Agar (CMA) is a well-established fungal medium that is a suitable substrate for chlamydospore production by Candida albicans and the maintenance of fungal stock cultures. This is a very simple formulation containing only cornmeal infusion and agar. The addition of glucose …

Oxidation-Fermentation (OF) Test: Introduction, Composition of the medium, Test Requirements, Principle, Procedure, Result -Interpretation, and Limitations

January 13, 2023January 6, 2023 by Medical Lab Notes

Fermentation Test Positive and Negative Results of Bacteria

Oxidation-Fermentation (OF) Test Introduction Hugh and Leifson developed an Oxidation-Fermentation (OF) basal medium in 1953. It is a recommended medium for the detection of oxidation or fermentation of carbohydrates by bacteria. This basal medium is useful to aid in the identification of gram-negative bacteria on …

Nitrate or Nitrite Reduction Test: Introduction, Composition of Medium, Principle, Test Requirements, Procedure, Result -Interpretation, and Limitations

January 13, 2023January 5, 2023 by Medical Lab Notes

Introduction of Nitrate or Nitrite Reduction Test The nitrate or nitrite reduction test uses to determine the ability of an organism to reduce nitrate to nitrite. Anaerobic metabolism requires an electron acceptor other than atmospheric oxygen. Many gram-negative bacteria use nitrate as the final electron acceptor. The …

DNase Test: Introduction, Composition, Principle, Test Requirements, Procedure, Result -Interpretations, and Limitations

January 13, 2023December 23, 2022 by Medical Lab Notes

Deoxyribonuclease (DNase) Test Positive and Negative Bacteria

Introduction of DNase Test for Bacteria DNase tests positive and negative bacteria as shown below image. This test is useful for the presumptive identification of Staphylococcus aureus which produces the enzyme deoxyribonuclease (DNase) from other Staphylococci which do not produce DNase. This test is also positive in the following …

ONPG Test: Introduction, Principle, Test Requirements, Procedure, Result -Interpretation, and Keynotes

January 13, 2023December 23, 2022 by Medical Lab Notes

ONPG Test Negative (left) and Positive Bacteria (right)

Introduction of ONPG Test ONPG test is useful in differentiating members of the family Enterobacteriaceae and genera Neisseria based on b-D-galactosidase activity. ONPG stands for o-Nitrophenyl-b-D-galactopyranoside. Here we discuss on ONPG Disk Test which is simple and easy to perform. Principle The ability of an organism to ferment lactose …