What color should Nitrazine paper turn with amniotic fluid?

Compare the color, which the moistened paper turns, to the standard color chart on the package of Nitrazine. Because amniotic fluid is neutral (pH 7.0) or slightly alkaline (pH 7.25), it will change the yellow color of Nitrazine Paper.

What is a Nitrazine pH test?

Nitrazine (Phenaphthazine) paper is used to measure the vaginal pH of expectant mothers to determine if the amniotic membrane has ruptured. The pH is used to determine if the fluid present represents amniotic fluid or vaginal fluid.

How do you test Nitrazine paper?


  1. Add one drop of buffer to Nitrazine test paper.
  2. Compare color to the paper dispenser’s pH scale. The pH must be within 0.5 of the designated pH to be acceptable.
  3. Document all results on the Control Sheet. If controls are out of range do not report any patient results until corrective action has been taken:

What does Nitrazine positive mean?

A chemical indicator used to determine pH, especially of vaginal secretions. It is often used in gynecological and obstetrical evaluations, e.g., to determine whether a pregnant woman has premature rupture of membranes with leaking amniotic fluid in the vaginal vault.

What makes Nitrazine positive?

However, a nitrazine test can give a false positive result if the sample is contaminated with blood, semen or antiseptics, or if the patient has vaginitis or cervicitis. On the other hand, false negative results can be obtained when the amount of fluid available for analysis is scant.

What is Nitrazine positive?

Nitrazine or phenaphthazine is a pH indicator dye often used in medicine. More sensitive than litmus, nitrazine indicates pH in the range of 4.5 to 7.5.

What color is a positive Nitrazine test?

Nitrazine Test The strips will turn blue if the pH is greater than 6.0. A blue strip means it’s more likely the membranes have ruptured.

What is pH of amniotic fluid?

Amniotic fluid normally has a pH of 6.5 or above whereas vaginal pH is 3.5–4.5.

What Colour is amniotic fluid?

Normal amniotic fluid is clear or tinted yellow. Fluid that looks green or brown usually means that the baby has passed the first bowel movement (meconium) while in the womb.