1. Agar slant
An agar slant is a screw-capped culture tube partly filled with an agar mix such as
nutrient agar, R2A agar etc.
Agar slants are created by bringing agar to the boiling point and pouring it into a
test tube.
To make it a slant tube the agar is allowed to cool with the tube laying at an angle,
resulting in a large surface area for spreading a culture.
Agar slants are used for storing pure cultures for a moderately long term.
Before the agar cools and solidifies, the test tube is set on its side.
Once the agar is cooled, the test tube can be stored upright, and the agar inside has
a slanted appearance.
Slanting the surface of the agar gives the bacteria a greater surface area on which
to grow in a test tube.
There is minimal risk of contamination or of losing the culture due to the medium
drying out because the small volume of air inside the tube and narrow opening
combine to limit water loss and exposure to outside air, including dust and other
particles.
Slants are created in test tubes that can be capped, which minimizes water loss.
Agar slants can be used to culture bacterial cells for identification.
When placed on a nutrient agar slant, bacterial cells will divide quickly and within
several hours will have produced enough cells to examine microscopically.
Agar slants are also useful in maintaining bacterial cultures, more so than stacks
of Petri dishes.
