TRANSIT VISA 5
1. (A) Our Water Quality Test is used to determine what is referred to as the Most Probable Number
(MPN). What is the Definition of MPN?
(B) Our Water Quality Testing involves a Total of nine (9) Test Tubes, each containing LSL Broth.
What is LSL Broth, why are we using this particular Medium for our Water Quality Test and why do
all nine (9) Tubes contain a small Inverted Test Tube?
A. Most Probable Number (MPN) is defined as a Statistical Estimate of the Number of
Coliform Bacteria present per 100 ml of water.
B. Lauryl Sulfate Lactose (LSL Broth) is used as a selective growth medium for
coliform bacteria. This medium can allow us to find the MPN of coliform bacteria within a
particular sample of water. It can also help to indicate the fermentation of lactose by encouraging
gas production. All nine test tubes contain small inverted test tubes to collect Hydrogen and
Carbon Dioxide produced by the coliforms dissolving into the medium. These two gases are the
end products of lactose fermentation.
1. (A) Our Water Quality Test is used to determine what is referred to as the Most Probable Number
(MPN). What is the Definition of MPN?
(B) Our Water Quality Testing involves a Total of nine (9) Test Tubes, each containing LSL Broth.
What is LSL Broth, why are we using this particular Medium for our Water Quality Test and why do
all nine (9) Tubes contain a small Inverted Test Tube?
A. Most Probable Number (MPN) is defined as a Statistical Estimate of the Number of
Coliform Bacteria present per 100 ml of water.
B. Lauryl Sulfate Lactose (LSL Broth) is used as a selective growth medium for
coliform bacteria. This medium can allow us to find the MPN of coliform bacteria within a
particular sample of water. It can also help to indicate the fermentation of lactose by encouraging
gas production. All nine test tubes contain small inverted test tubes to collect Hydrogen and
Carbon Dioxide produced by the coliforms dissolving into the medium. These two gases are the
end products of lactose fermentation.
