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Key Documents

1.09261

Sigma-Aldrich

Lugol′s solution (diluted iodine-potassium iodide solution)

for the Gram staining method

Synonym(s):

Iodine-potassium iodide solution

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About This Item

UNSPSC Code:
41116130
NACRES:
NA.74

Quality Level

form

liquid

IVD

for in vitro diagnostic use

technique(s)

microbe id | staining: suitable

pH

3.5 (20 °C in H2O)

bp

100 °C/1013 hPa

density

1.01 g/cm3 at 20 °C

application(s)

clinical testing
diagnostic assay manufacturing
hematology
histology

storage temp.

15-25°C

General description

Lugol′s solution (diluted iodine-potassium iodide solution - for the Gram staining method, is a ready-to-use solution used in Bacteriology, for example, for the staining of Gram bacteria. In bacteriology, the Gram staining allows a fast differentiation of bacteria in Gram-positive and Gram-negative. The mureine structure of the bacteria wall is the basis of the color affinity. In the first step, bacteria will be stained with crystal violet (Product number 1.09218), an aniline dye. After the treatment with iodine solution (Lugol′s solution), a dye-iodine complex will form. During the decolorizing step (Gram′s decolorizing solution, Product number 1.10218), this complex stays in the multilayer mureine structure of the cell wall of Gram-positive bacteria - they will appear blue-violet. Gram-negative bacteria, by contrast, have a cell wall consisting of a single-layered murein structure, and correspondingly re-release the staining dye with the decoloring solution. Gram-negative bacteria will be counterstained with safranine solution (Product number 1.09217) and will then appear pink to red.
Lugol′s solution (diluted iodine-potassium iodide solution) is capable of staining up to 500 slides. This product is registered as IVD and CE marked. For more details, please see instructions for use (IFU). The IFU can be downloaded from this webpage.

Storage Class Code

12 - Non Combustible Liquids

WGK

WGK 2

Flash Point(F)

Not applicable

Flash Point(C)

Not applicable


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