What is the rate law of the fading of crystal violet?
What is the Rate Law of the Fading Crystal Violet Reaction Using Beer’s Law? The rate law for this reaction is in the form: rate = k[CV+]m[OH]n, where k is the rate constant for the reaction, m is the order with respect to crystal violet (CV+), and n is the order with respect to the hydroxide ion.
Does the rate of fading of phenolphthalein depend on the concentration of the dye?
The rate of the fading of phenolphthalein depends on ionic strength or the ion concentration of the reaction solutions.
What part of the cell does crystal violet stain?
Bacteria cell walls are stained by the crystal violet. Iodine is subsequently added as a mordant to form the crystal violet-iodine complex so that the dye cannot be removed easily. This step is commonly referred to as fixing the dye.
What is the difference between a basic dye and an acidic dye?
Basic dyes have a net positive charge and bind to components of cells and tissues that are negatively charged. Acidic dyes have a net negative charge and bind to components of cells and tissues that are positively charged.
What is an example of negative stain?
Some suitable negative stains include ammonium molybdate, uranyl acetate, uranyl formate, phosphotungstic acid, osmium tetroxide, osmium ferricyanide and auroglucothionate. The structures which can be negatively stained are much smaller than those studied with the light microscope.
Why is Nigrosin used as a negative stain?
We use nigrosin as our negative stain. This means that the stain readily gives up a hydrogen ion and becomes negatively charged. Since the surface of most bacterial cells is negatively charged, the cell surface repels the stain. The glass of the slide will stain, but the bacterial cells will not.
Is Nigrosin positive or negative?
Nigrosin is an acidic stain which becomes negatively charged. Since the surface of most bacterial cells is negatively charged, the cell surface repels the stain. The glass of the slide will stain, but the bacterial cells will not.