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Using an aseptic technique, bacteria are placed on a slide and heat fixed. The slide is then suspended over a water bath with some sort of porus paper over it, so that the slide is steamed . Malachite green is applied to the slide, which can penetrate the tough walls of the endospores, staining them green.
Once stained, they do not decolourize. The addition of heat during the staining process is a huge contributing factor. [15] Heat helps open the spore's membrane so the dye can enter. The main purpose of this stain is to show germination of bacterial spores.
Using aseptic technique, prepare and air dried heat fixed slide with the desired organism. Prepare a boiling water bath. Cover the slide with a piece of paper towel and place on staining rack over the water bath. Flood the paper towel on the slide with Malachite Green ( primary stain). Steam the slide for 5 to 7 minutes (mordant).
Applying a primary stain (crystal violet) to a heat-fixed smear of a bacterial culture. Heat fixation kills some bacteria but is mostly used to affix the bacteria to the slide so that they do not rinse out during the staining procedure. The addition of iodine, which binds to crystal violet and traps it in the cell
An inoculation loop (also called a smear loop, inoculation wand or microstreaker) is a simple tool used mainly by microbiologists to pick up and transfer a small sample of microorganisms called inoculum from a microbial culture, e.g. for streaking on a culture plate. [1] [2] This process is called inoculation.
Food grading involves the inspection, assessment and sorting of various foods regarding quality, freshness, legal conformity and market value. [1] [2] Food grading is often done by hand, in which foods are assessed and sorted. [1] [2] Machinery is also used to grade foods, and may involve sorting products by size, shape and quality.
The purpose of IMF foods is to achieve a water activity that the food can be stored safely without refrigeration. However, the food is not sterile. Staphylococcus aureus is a microorganism of concern as it can grow and produce specific enterotoxins in water activities of 0.83-0.86 under aerobic conditions. [2]
Blood film stained with Giemsa showing Plasmodium (center of image), the parasite that causes malaria infections.. In 1891 Romanowsky [8] [9] [10] developed a stain using a mixture of eosin (typically eosin Y) and aged solutions of methylene blue that formed hues unattributable to the staining components alone: distinctive shades of purple in the chromatin of the cell nucleus and within ...