Plasma methemoglobin

The methemoglobin (Hi) can oxidize hemoglobin to high-iron (Fe3+) hemoglobin by various oxides, and loses oxygen carrying capacity. The methemoglobin is reddish-brown with four absorbance bands of 634, 578, 540 and 500 nm. According to the absorbance, the hemoglobin concentration can be obtained. Therefore, it is clinically useful to diagnose certain degenerative hemoglobinemia.

Basic Information

Specialist classification: cardiovascular examination classification: biochemical examination

Applicable gender: whether men and women apply fasting: fasting

Analysis results:

Below normal:
Reduction can be seen in various anemia, leukemia, postpartum, blood loss and so on.

Normal value:
Male: 130-170g/L
Female: 110-150g/L
Children: 120-150g/L
Newborn: 170-200g/L

Above normal:
Physiological increases can be seen in newborns, plateaus, etc. Pathological increases are seen in polycythemia vera, compensatory polycythemia.



Tips: Before the examination, the diet is light and alcohol is prohibited. Check for an empty stomach in the morning. Normal value

Male 130 ~ 170g / L; female 110 ~ 150g / L; newborn 170 ~ 200g / L; children 120 ~ 150g / L.

Clinical significance

1. Physiological increase is seen in newborns, plateaus, etc.

2, pathological increase seen in polycythemia vera, compensatory polycythemia.

3, reduce can be seen in various anemia, leukemia, postpartum, blood loss and so on.

Low results may be diseases: anemia, polycythemia vera, secondary erythrocytosis, high results may be diseases: high altitude polycythemia, hemorrhagic shock, congenital leukemia considerations

1. HiCN is the most accurate method for various hemoglobin assays. All hemoglobins except HbS and HbC can be converted into HiCN. The reagents introduced in this paper are recommended by the International Hematology Standardization Committee (ICSH). Since the millimolar absorbance coefficient of HiCN is internationally recognized, it can be directly calculated from the absorbance coefficient using a rigorously calibrated advanced spectrophotometer. This calculation is not a routine method of the laboratory.

2, the absorbance measured at 540nm, 251 is the blood dilution factor, 11.0 is the Hb molecular monomer millimolar absorbance coefficient, 1.0 is the light path, 16114.5 is the monomer molecular weight, except 1000 is converted from milligrams (mg) to grams (g) .

3. The diluent should be stored in a brown glass bottle and should not be stored in a plastic bottle. Otherwise, the cyanide ion is adsorbed on the plastic bottle wall, so that the measurement result is low.

4, the dilution contains potassium cyanide, do not use mouth to aspirate. After the determination, the waste liquid should be diluted with an equal amount of water, and added with 35 ml of sodium hypochlorite solution per liter, mixed, opened, and placed in the sewer for one night.

5, there are many methods for the determination of hemoglobin. At present, none of the reported methods have established their own standards. The use of such methods should be cautious and must be evaluated by using the HiCN method as a reference method. It is especially important to note that the commercially available blood red protein control solution is a HiCN method control solution, which is obviously biased for other methods.

Inspection process

Check operation:

Take 20 μl of blood, add 5 ml of the diluent, mix, stand for 5 min, measure with a spectrophotometer or colorimeter, at 540 nm wavelength, or green filter, correct the absorbance with water to zero, measure the absorbance or check the standard curve. , that is, the result.

Not suitable for the crowd

Those without examination indications should not be tested.

Adverse reactions and risks

Dizziness or fainting: When blood is drawn, due to emotional overstress, fear, reflex caused by vagus nerve excitability, blood pressure drop, etc., the blood supply to the brain is insufficient to cause fainting or dizziness.