What is the procedure for heat fixation?

There are several steps to be carried out during the procedure for heat fixation. The first step is to use a wax pencil to draw a circle onto a sample slide to separate each type of bacteria that is being studied. If only one type of bacteria or single mixed bacteria is being studied, separation is not necessary. The second step is to prepare a bacterial smear, in order to properly see individual bacteria. A sample of a bacterial colony must be mixed into water or saline. For properly placing the sample onto the slide, first a drop of water from a pipette is applied onto the wax circle.  One must then use a sterilized inoculation loop to collect a small amount of a bacterial colony. The bacteria is then mixed into the water drop and spread over a wide area of the slide. The smear should then be air dried, and heat fixed with a Bunsen burner. The slide should pass the flame very quickly and not be heated excessively. It should be passed through the flame of a Bunser burner 3 or 4 times, with the smear side facing up. The slide can also be passed through a microincinerator as an alternative to a Bunsen burner. A microincinerator uses infrared heat inside a ceramic tube; when it reaches optimum sterilization temperature of 900 degrees celsius, the loop is sterilized within 5-7 seconds. Once the slide is properly heat fixed using either technique, it is then ready to be stained.