let's see below the technique of realization of degree first we have the culture to perform the great which is a fresh pure culture with isolated colonies as you can see we are going to take a glass slide which is a slide we are going to make a mark in the area where we are going to perform the smear so as not to lose it then when we are performing the valuation stage we burn the bacteriological lance we incinerate it which is the way to sterilize it by heat and once it is cold we place it inside the bottle that contains the water and we are going to deposit that drop on the slide to then be able to place the colonies in that place then we burn the lance again to proceed to touch a colony that is on that culture plate and in which we want to identify by means of the technique of great when it is cold we are going to touch a colony there we are going to emulsify them with the water that we put so that those bacterial cells are going to begin to spread in that preparation as you can see we are going to do a drying process so that they adhere to this object slide and then they are not going to be lost with the staining that we are going to perform with the different colors to fix it we pass it three times through the flame of the lighter it is one of the ways there are to fix the smear and then proceed to its coloring then we carry out the staining itself and it is a differential attention we are going to have different results depending on the composition of the wall the first dye to use is crystal violet which is a violet dye it is placed covering the entire extension of the smear that we prepare and it is left to act for 1 minute this dye will penetrate the cytoplasm bacteria would not have structures then the excess dye is washed with water it is a step that is carried out between dye and the different stages it is always washed after finishing a stage with plenty of water we proceed to the second stage of the grant technique that place then which is a compound I given that what it is going to do for 30 seconds is a stronger interaction between the crystal violet and the components of the cell with a negative charge you wash with water always between step and step the excess water is removed and then comes a key stage which is the decolorization stage with a mixture of alcohol acetone This mixture will dissolve the primary dye on the one hand and on the other hand also dehydrate the pores of the bacterial wall is decolorizing alcohol acetone is placed covering the entire preparation then once again rinse with plenty of water and remove the excess water from the slide here a very important step will occur depending on the type of bacterial cells we have the final step is a contrast staining with a dye that is the zafra nina which is pink that should also be placed covering the entire preparation as can be seen in the image let it act for 1 minute wash it with plenty of water and finally dry the preparation well once it is dry a drop of immersion oil is placed which is visualized in the clear field microscope with the inversion lens which is time