Diffential Staining
Differential Staining
Cynthia Alonzo, M.S. Version 42-0242-00-01
Lab RepoRt assistant
This document is not meant to be a substitute for a formal laboratory report. The Lab Report Assistant is simply a summary of the experiment’s questions, diagrams if needed, and data tables that should be addressed in a formal lab report. The intent is to facilitate students’ writing of lab reports by providing this information in an editable file which can be sent to an instructor.
obseRvations
Questions
A. What is a differential stain? How is it different from a simple stain?
the use of two or more stains to categorize cells into groups. simple stain uses one dye and shows only structure, morphology and size. a differential stain uses two or more dyes and is used to show morphology and distinguish cell types
B. What is the difference between Gram-positive and Gram-negative cell walls?
Structure: Have thick layer of peptidoglycan over inner cytoplasmic membrane. lack LPS-lipopolysaccharides
Gram negative appear: pink to transfer to red Structure: In gram negative bacteria the peptidoglycan layer is thinner and is located between space of the outer and inner cytoplasmic membrane. cell wall contains LPS which make them virulent
C. What is the purpose of crystal violet in the Gram’s stain procedure?
Crystal violet stain is a histological dye used as a stain in Gram's Method of categorizing bacteria. The purpose of crystal violet in the Gram's stain procedure is to differentiate bacteria into two different groups of pink and purple colours with gram positive being purple and gram negative being pink in colour.
D. What is the purpose of iodine in the Gram’s stain procedure? What is a mordant? Keeps
Cynthia Alonzo, M.S. Version 42-0242-00-01
Lab RepoRt assistant
This document is not meant to be a substitute for a formal laboratory report. The Lab Report Assistant is simply a summary of the experiment’s questions, diagrams if needed, and data tables that should be addressed in a formal lab report. The intent is to facilitate students’ writing of lab reports by providing this information in an editable file which can be sent to an instructor.
obseRvations
Questions
A. What is a differential stain? How is it different from a simple stain?
the use of two or more stains to categorize cells into groups. simple stain uses one dye and shows only structure, morphology and size. a differential stain uses two or more dyes and is used to show morphology and distinguish cell types
B. What is the difference between Gram-positive and Gram-negative cell walls?
Structure: Have thick layer of peptidoglycan over inner cytoplasmic membrane. lack LPS-lipopolysaccharides
Gram negative appear: pink to transfer to red Structure: In gram negative bacteria the peptidoglycan layer is thinner and is located between space of the outer and inner cytoplasmic membrane. cell wall contains LPS which make them virulent
C. What is the purpose of crystal violet in the Gram’s stain procedure?
Crystal violet stain is a histological dye used as a stain in Gram's Method of categorizing bacteria. The purpose of crystal violet in the Gram's stain procedure is to differentiate bacteria into two different groups of pink and purple colours with gram positive being purple and gram negative being pink in colour.
D. What is the purpose of iodine in the Gram’s stain procedure? What is a mordant? Keeps