II. Indications

III. Mechanism

  1. Nitrazine Paper relies on Prussian blue reaction
  2. Requires alkaline paper to cause reaction

IV. Technique

  1. Obtain fluid for exam (usually after Vaginal Pooling)
  2. Place Nitrazine Paper in fluid
    1. Paper turns bright blue in alkaline fluid

V. Interpretation: Nitrazine Paper

  1. Normal Vaginal pH 4.5-6.0: Paper does not change color
  2. Ruptured Vaginal pH 7.1-7.3: Suggests PROM (paper blue)

VI. Causes: False Positive Nitrazine positive (pH >7)

  1. Blood
  2. Semen
  3. Antiseptic solutions
  4. Urine with increased pH (alkaline urine)
  5. Vaginal infection (Bacterial Vaginosis)

VII. Efficacy

  1. Accuracy for amniotic fluid: 87-97%

Images: Related links to external sites (from Google)

Ontology: Nitrazine yellow (C0068806)

Concepts Indicator, Reagent, or Diagnostic Aid (T130) , Organic Chemical (T109)
MSH C013617
SnomedCT 86750008
English 2-((2,4-dinitrophenyl)azo)-1-naphthol 3,6-disulfonic acid, 3,6-naphthalenedisulfonic acid, 2-((2,4-dinitrophenyl)azo)-1-hydroxy, 3-((2,4-dinitrophenyl)azo)-4-hydroxy-2,7- naphthalenedisulfonic acid, DNPNS, nitrazine paper, nitrazine yellow, phenaphthazine, Phenaphthazine, PHENAPHTHAZINE, Nitrazol yellow, Nitrazine yellow stain (substance), Nitrazine yellow stain, Nitrazine yellow, Nitrazine yellow (substance), Nitrazine Paper
Spanish amarillo de nitrazina (sustancia), amarillo de nitrazina, colorante amarillo de nitrazina (sustancia), colorante amarillo de nitrazina