Raj. CHO -2020
Biochemistry & Nutrition
Easy

What is used to measure the amount of Hemoglobin?

Appeared in: Raj. CHO -2020

Explanation

  • N/10 HCl (Hydrochloric acid) is the specific reagent used in the Sahli's acid hematin method for estimating hemoglobin.
  • This acid lyses the red blood cells to release hemoglobin.
  • It then converts the iron in hemoglobin into a stable, brown-colored compound known as acid hematin.
  • The concentration of hemoglobin is determined by diluting this solution with distilled water until its color visually matches a standard brown glass comparator.

Why Other Options Were Wrong

  • Option A: NaCl (Sodium Chloride) is common salt. In medicine, it's primarily used to prepare isotonic saline solutions for intravenous infusions or as a diluent. It does not have the chemical properties to convert hemoglobin into a measurable colored compound.
  • Option C: NaOCl (Sodium Hypochlorite) is the active ingredient in bleach. It is a powerful disinfectant and oxidizing agent that would denature and destroy the hemoglobin protein, making any measurement impossible.
  • Option D: NaOH (Sodium Hydroxide) is a strong alkali or base. While an 'alkaline hematin' method for hemoglobin estimation exists, it is less common and uses a different principle. The standard and widely known Sahli's method is an 'acid hematin' method, which specifically requires an acid like HCl.

Related Visual

Visual explanation — Related Visual
  • Visual 1: Diagram: Sahli's hemoglobinometer, illustrating the comparator with standard brown glass rods, the graduated Sahli's tube, and the pipette for measuring blood.
  • Visual 2: Flowchart: A step-by-step visual guide of the Sahli's method, from adding blood to HCl to the final color matching and reading.
Clinical Relevance
  • Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Reagent for Hemoglobin Estimation (Sahli's Method) as background academic context rather than a clinical decision trigger.
  • Hemoglobin measurement is a fundamental component of a complete blood count (CBC) and is essential for diagnosing and managing anemia and polycythemia.
  • Nurses frequently monitor hemoglobin levels to assess a patient's response to treatment (e.g., iron supplements, blood transfusions) and to evaluate blood loss after surgery or trauma.
  • Normal hemoglobin ranges are crucial to know: Males (14–18 g/dL) and Females (12–16 g/dL). Values below these ranges indicate anemia.
How to Approach the Question
  • First, identify the core of the question, which asks for the specific chemical used to measure hemoglobin.
  • Recall the common manual laboratory methods for hemoglobin estimation. The Sahli's method is a classic technique often taught in basic nursing and medical laboratory courses.
  • Remember the principle of the Sahli's method, which is also known as the 'acid hematin' method.
  • The name 'acid hematin' is a strong clue that an acid is required. Look for an acid among the options.
  • N/10 HCl is hydrochloric acid. The other options are a salt (NaCl), a bleach (NaOCl), and a base (NaOH).
  • Select N/10 HCl as it is the only acid and directly corresponds to the principle of the Sahli's method.
Concept Tested & Keywords
  • Concept Tested: Reagent for Hemoglobin Estimation (Sahli's Method)
  • Stem keywords: measure, amount, Hemoglobin
  • Lead-in keywords: What is used
  • Negative lead-in flag: false

Question ID

Q9PGFYXSL5wSJd7ak31uEv

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