CH. 3 -- Isolation Streak Plate

Question 1

isolation streak plate

Answer 1

is a widely used method to separate individual bacteria from mixtures – in result, having fewer and fewer bacteria as you continue around the plate

Question 2

isolated colonies

Answer 2

formed when the concentration of bacteria becomes so low that a single bacteria comes off the loop – creating a single colony

Question 3

colony

Answer 3

arised from a single bacterium that divided repeatedly over time to form a mass of millions of cell – therefore, all the bacteria in the colony should be the same

Question 4

quadrant technique

Answer 4

when using a petri dish, we split into sections (quadrants) – the first streak will cover half the plate while the next 2 will each cover half of the rest (second half) of plate

Question 5

DO::

Answer 5

1. When streaking plate, hold the lid at an angle covering the plate or you may add some extra microbes to your mixture, and relid when not streaking
2. Touch loop gently to the agar. Try not to dig or cut into surface.
3. Keep plate in the incubator lid side down to prevent condensation forming on the specimen.

Question 6

first streak area

Answer 6

will show heavy, confluent growth

Question 7

second streak area

Answer 7

growth is starting to thin out, some individual colonies appearing

Question 8

third streak area

Answer 8

much lighter growth, individual isolated colonies