Deepak Singh

How Bacterial Cell Walls Decide the Final Colour in Gram Staining

A stained bacterial smear can reveal an unexpected contrast under the microscope. Some are a deep purple shade and others appear pink. The contrast raises an important question: why do bacterial cells respond differently to the same stains?

Gram staining answers that question with a series of carefully controlled steps. The method separates two main groups based on differences in the bacterial cell walls. It is a mixture of several reagents, each having a special part to play. The last colour provides information on cell behaviour during the staining process.

What Is Gram Staining?

Gram Staining method is used to differentiate bacteria according to their cell wall structure. It classifies bacteria into Gram positive and Gram negative.

The method begins by adding a purple primary stain to the bacterial cells.

Various Approaches for Microbiological Assessment of Water Quality

Various Approaches for Microbiological Assessment of Water Quality

Water is a critical resource for sustaining life. To ensure the safety and purity of water, it becomes imperative to employ robust methodologies for evaluating its microbial content. The assessment of harmful microorganisms in water sources hinges on microbiological testing. In this blog, we will delve into various techniques for microbiological evaluation of water quality.

Techniques for Water Microbial Count:

1.  Membrane Filtration Method: The widely adopted technique involves passing a known volume of water through a 0.45-micron membrane filter. Microorganisms are retained on the filter, then transferred to a solid culture medium for growth and enumeration. Our Membrane Filtration Funnel, paired with CN Gridded Membranes, provides an ideal solution for this technique.

2. Multiple-Tube Fermentation