My vlog is Separation of bacterial morphology in mixed culture let's start a blog mixed growth

When agar plates are struck for isolation,it will be simple matter to select isolated colonies for sub culture.On ocassion, however, growth may be so crowded that it is difficult to pick individual isolated colony.Several manipulation are available to the micro biology.

Gram stain examination of culture

Preliminary impression, based on observation of colony characteristics, can be further confirmed by studying gram stained smears,a technique that is relatively simple to perform.The top and centre of the colony to be studied is first touched with the end of a straight inoculating wire,taking care not to touch the adjacent agar.The portion of the colony to be sampled is emulsified in a small drop of water or physiologic saline on a microscope slide to disperse the individual bacterial cell.After the slide has air dried,the bacterial film is fixed to the glass surface either by using heat, quickly passing the slide four or five times through the flame of a bunsen burner,or by flooding with methanol or ethanol for a few minutes.The fixed smear is then placed on a staining rack and gram stain is performed.

Stained smear

The stained smears should be examined microscopically.Tge techniques for picking an isolated bacterial colony with a straight wire for subculture to another medium.The techniques for preparing a smear for gram stain.The top portion of an isolated bacterial colony, touched with an inoculating wire or loop,then the tip of the loop is submerged in a drop or water or physiologic saline on a glass slide.The inoculum is then emulsified and the preparation is left to air dry before heat fixation and staining.

Oil immersion

Using an oil immersion objective.In addition to the gram stain reaction of the bacterial cell gram positive bacteria appear blue,gram negative bacteria appear red or pink three other characters are helpful in making a preliminary identification of isolates size and shape of the bacterial cell, arrangements of the bacterial cell and presence or lack of specific structure or organelles.

In making a preliminary identification of bacterial isolates,the micro biologist should evaluate each of thes characteristic.A series of photomicrographs of several stains illustrating a number of the morphologic cell types and spatial arrangements of bacteria commonly encountered in clinical laboratory.