How do you read a nitrate reduction test?

How do you read a nitrate reduction test?

Add one dropper-full of sulfanilic acid and one dropper-full of an α-naphthylamine to each broth.

1. At this point, a color change to RED indicates a POSITIVE nitrate reduction test. If you get a red color, then you can stop at this point.
2. No color change indicates the absence of nitrite.

What indicates a positive result for nitrate reduction?

An organism may be reported as nitrate-positive if a red color develops in the medium after Nitrate reagents A and B are added to the medium, indicating that the organism has reduced nitrate to nitrite.

What is a negative nitrate reduction test?

A negative zinc reduction (no color change) test, in combination with a negative nitrite reaction, is presumptive indication that the nitrate was reduced beyond the nitrite stage. Although a very common end product of nitrite reduction is nitrogen gas, other end products may be formed.

What are the 2 major end product of nitrate reduction?

There are two separate pathways for this dissimilatory process, one called dissimilatory nitrate reduction to ammonium, where ammonium is the end product, and one called denitrification, where a mixture of gaseous products including N2 and N2O is formed.

What does nitrate positive mean?

The presence of nitrites in urine most commonly means there’s a bacterial infection in your urinary tract. This is usually called a urinary tract infection (UTI). A UTI can happen anywhere in your urinary tract, including your bladder, ureters, kidneys, and urethra.

Do nitrites in urine mean infection?

A urinalysis, also called a urine test, can detect the presence of nitrites in the urine. Normal urine contains chemicals called nitrates. If bacteria enter the urinary tract, nitrates can turn into different, similarly named chemicals called nitrites. Nitrites in urine may be a sign of a urinary tract infection (UTI).

What is the purpose of the nitrate reduction test?

The nitrate reduction test is a qualitative procedure for determining the ability of bacteria to reduce nitrate. In the reaction, nitrate is reduced to nitrite, which may then be further reduced to nitrogen gas or ammonia.

Is nitrate positive or negative?

Nitrates are chemical compounds which, among other defining characteristics, contain the polyatomic ion nitrate, which is composed of one atom of nitrogen and three atoms of oxygen, together having a single net negative charge. Nitrates are commonly seen in the study of inorganic chemistry as well as organic chemistry.

What is positive nitrate reduction?

Positive – A nitrate reduction test is positive if the color changes to cherry red after adding the reagent. If the additional step was taken such as adding a zinc powder, the result is positive if the color of the medium does not turn to red after adding zinc powder. (3, 6, and 8)