How do you perform a Gram stain procedure?
There are six basic steps:
- Apply a smear of bacteria on to a slide.
- Add about 5 drops of Hucker’s Crystal Violet to the culture.
- Add about 5 drops of iodine solution to the culture.
- Tilt slide and decolorize with solvent (acetone-alcohol solution) until purple color stops running.
- Add about 5 drops of Safranine O.
What are the steps in a Gram stain and the possible results?
Steps of Gram Staining Application of mordant: The iodine solution (mordant) is added to form a crystal violet-iodine (CV-I) complex; all cells continue to appear blue. Decolorization step: The decolorization step distinguishes gram-positive from gram-negative cells.
What is the correct order for the Gram stain?
The stains are applied to a smear of bacteria on a microscope slide in the following order: crystal violet, Gram’s iodine, decolorizing agent, and safranin.
What are the steps of the Gram stain quizlet?
Steps of gram staining technique:
- Apply primary stain (crystal violet). All bacteria are stained purple by this basic dye.
- Apply mordant (Gram’s iodine).
- Apply decolorizing agent (ethyl alcohol or ethyl alcohol acetone).
- Apply secondary stain or counterstain (safranin).
How do you prepare a Gram stain for a smear?
Preparation of the smear is as follows:
- From broth: Using a cooled, sterile loop, place a loopful of broth on the slide and spread in a circular motion to about 1 cm in diameter.
- From plated media: Place a drop of sterile water or saline on the slide. Select the isolated colony to be stained.
Which is applied first in Gram staining?
crystal violet dye
The first step in gram staining is the use of crystal violet dye for the slide’s initial staining. The next step, also known as fixing the dye, involves using iodine to form crystal violet- iodine complex to prevent easy removal of dye.
What are the 4 steps of the Gram stain?
The performance of the Gram Stain on any sample requires 4 basic steps that include applying a primary stain (crystal violet) to a heat-fixed smear, followed by the addition of a mordant (Gram’s Iodine), rapid decolorization with alcohol, acetone, or a mixture of alcohol and acetone and lastly, counterstaining with …
What are the 4 stains used in Gram staining?
Reagents Used in Gram Staining
- Crystal Violet, the primary stain.
- Iodine, the mordant.
- A decolorizer made of acetone and alcohol (95%)
- Safranin, the counterstain.
What is the first step in Gram staining?
The first step in gram staining is the use of crystal violet dye for the slide’s initial staining. The next step, also known as fixing the dye, involves using iodine to form crystal violet- iodine complex to prevent easy removal of dye.
What is the most critical step in the Gram staining procedure?
The critical step of the Gram staining procedure is the decolorization step. Hold the slide in a tilted downward position and allow the decolorizer to flow over the smear.
What are the steps in a Gram stain?
Heat-fix a smear of a mixture of the bacterium as follows: a.
How to prepare a Gram stain?
Place a small drop of bacterial sample on a slide.
What is the most critical step in a stain?
the stain. The step that is most crucial in effecting the outcome of the stain is the decolorizing step. Over-decolorizing will lead to an erroneous result where gram-positive cells may stain pink to red indicating a gram-negative result, and under-decolorizing will lead to an
How long should a Gram stain take?
Gram Staining Procedure/Protocol: Flood air-dried, heat-fixed smear of cells for 1 minute with crystal violet staining reagent. Please note that the quality of the smear (too heavy or too light cell concentration) will affect the Gram Stain results. Wash slide in a gentle and indirect stream of tap water for 2 seconds.