Simple staining procedure pdf

In simple staining we use different types of dyes, based on the type of strains. Some example of dyes are Crystal violet for detection of gram-positive bacteria, safranin for detection of gram-negative bacteria, carbol fuchsin for acid fast bacteria, and methylene blue for non-acid fast bacteria, Malachite green for endospore, etc.

In simple staining, the bacterial cells are first fixed on a clean, oil-free slide and then flooded with stain safranin, methylene blue, carbol fuchsin, Crystal violet, etc. This stain will produce a distinctive contrast between the organism and its background so that we can easily distinguish them.

These stains will readily give up a hydroxide ion or accept a hydrogen ion, as result they become positively charged. Hence, the bacterial cell wall components and cytoplasm are negatively charged, which strongly attracts with the and binds to the cationic chromogen. Observe the slide under microscope by using the oil-immersion technique and make a drawing of each organism.

On the basis of observation write a description of each organisms; indicating color, shape and arrangement of cell. How satisfied are you with this article? Name Email. Staining Simple Staining Procedure, Principle, Result The main purpose of simple staining is to determine the cell shape, size, and arrangement of bacterial cells.

Sourav Bio. This article writter by Sourav Bio on March 31, The steps for were compared with those of thick and thin air-dried decolourisation and counterstaining were similar to the smears through McNemar test,4 which is a statistical conventional method.

The reagent was filtered after method to assess the significance of relationship every batch of staining and reused, topping the carbol between diagnostic procedures, where neither procedure fuchsin to ensure proper immersion of slides.

Aspirates can be designated as the gold standard. Three smears viz. A air-dried thick, B air-dried thin and C thick smears wet fixed in ethanol Results for 20 min were made. Mycobacterial cultures of puru- Of the 42 cases analysed, culture was positive in The study Concordance between culture and microscopy was seen group comprised of 42 patients in whom all three smear in 20 air-dried thick, 18 air-dried thin and 19 ethanol- types and culture reports were available.

Two types of fixed thick smears. Statistical analysis showed that, air-dried smears, A and B, were stained by the conven- keeping culture results as gold standard, positive predic- tional Ziehl—Neelsen method. Smears in group C, that tive accuracy for AFB detection by all the three smear is, thick smears wet fixed in ethanol for 20 min were types, that is, air-dried thick, air-dried thin and ethanol- stained by the modified method.

Overall predictive accuracy was racy of the three different types of smears was per- None of the AFB staining methods under study Thick air-dried 42 20 0 14 8 Thin air-dried 42 18 0 16 8 Thick ethanol-fixed 42 19 0 15 8 Most importantly, the modifications made pro- Grossly vided results comparable to conventional Ziehl—Neelsen material loss was noticed in 23 air-dried thick smears as staining technique.

The positive, negative and overall against four ethanol-fixed thick smears. This is important as sensitivity and specific- ity are independent of the disease frequency in the Discussion population. They are not setting-specific. Contents 1 Procedure 1. About Acharya Tankeshwar Articles. Hello, thank you for visiting my blog. I am Tankeshwar Acharya. Klebsiella aerogenes and Escherichia coli were identified to be gram negative bacteria.

Questions : 1 What colour would you expect Staph. The role of iodine in gram stain is to act a mordant a substance that sets dye. It functions to form large crystals with the crystal violet dye. When the crystal violet dye mixes with iodine, it will form a crystal violet iodine CVI complex.

This complex is larger than the crystal violet molecule and is easier for the gram positive bacteria to retain the blue dye. If the iodine step was omitted in the gram staining procedure, the crystal violet dye that is used will not be able to form the CVI complex. Therefore, Staph. Initially, we use the crystal violet dye to stain the bacterial cells. The colour of this dye can vary from purple to dark blue. If methylene blue was used for counterstaining, it would be difficult to differentiate between a gram positive bacteria and a gram negative bacteria as methylene blue and the crystal violet dye have almost the same colour.

Therefore, methylene blue will not work as an effective counter stain. However if safranine is used, we can clearly see the contrast between the blue colour of the crystal violet dye and the red colour of the safranine making it easier for us to distinguish between a gram positive and a gram negative bacteria.

Discussion Microbiology Simple Stain October Microbiology January 0. Microbiology April 0. Microbiology March 0.