solution. Mix well. Dilute to the mark with distilled water. This reagent remains stable
under refrigeration at 4C for approximately 1 month. See figure 6-1.
Figure 6-1. Dithionite tube test interpretation.
WARNING:
Sodium dithionite reagent may ignite if allowed to become damp.
Use only clean dry utensils in handling.
(3)
Urea (USP).
c. Procedure.
(1)
Pipet 2 ml of dithionite reagent in 12 x 75 mm test tube.
(2)
Add 0.02 ml of well-mixed anticoagulated blood (collected in EDTA).
(3) Mix the contents and al1a.v to stand at roan temperature for 5 minutes
(see figure 6-1).
(4) After 5 minutes examine the tube for turbidity against a lined reader.
Hemoglobin 5, if present, produces turbidity in the tube .
d. Sources of Error.
(1)
The use of 10 x 75 mm test tubes could cause a false negative result.
(2) The dithionite reagent has a limited stability. The freshness of this
reagent must be checked with positive and negative controls. The test should show the
blue-pink color of reduced hemoglobin and adequate lysis of erythrocytes.
MD0853
6-10