2. The reason why decreased chloride levels often occur
in acute infections is not clear.
3. Chloride measurements are of limited value in
renal diseases for the reason that plasma chloride
can be maintained near normal limits even when a
considerable degree of renal failure is present.
4. Increased chloride levels occur in
5. Decreased chloride levels occur in
j. Acute infections such as pneumonia
k. Use of drugs such as mercurial and chlorothiazide
1. The plasma chloride concentration of infants is usually
higher than that of children and adults.
2. Many drugs may cause a change in chloride levels.
1. In intravenous therapy, if the solution contains
100 mEq/L, there is ample chloride present for the
correction of urine metabolic acidosis.
2. If an electrolyte disorder is suspected, daily weight and
accurate intake and output should be recorded.
(Courtesy: Tulip Group of Companies)
For the determination of iron and total iron binding capacity
in serum (laboratory reagent for professional use only).
Iron found in blood is mainly present in the hemoglobin
of the RBCs. Its role in the body is mainly in the
transportation of oxygen and cellular oxidation. Iron is
absorbed in the small intestine, and bound to a globulin
in the plasma, called transferrin and transported to
the bone marrow for the formation of hemoglobin.
Increased serum levels are found in hemolytic anemias,
hepatitis, lead and iron poisoning. Decreased serum
levels are found in anemias caused by iron deficiency
due to insufficient intake or absorption of iron, chronic
blood loss, late pregnancy and cancer. Increase in TIBC
is found in iron defecient anemias and pregnancy.
Decrease in TIBC is found in hypoproteinemia,
hemolytic/pernicious/sickle cell anemias, inflammatory
Iron, bound to transferrin, is released in an acidic medium
and the ferric ions are reduced to ferrous ions. The Fe (II)
ions react with ferrozine to form a violet colored complex.
Intensity of the complex formed is directly proportional to
the amount of iron present in the sample. For TIBC, the
serum is treated with excess of Fe (II) to saturate the iron
binding sites on transferrin. The excess Fe (II) is adsorbed
and precipitated and the Iron content in the supernatant is
Fe (II) + Ferrozine Violet colored complex
Serum Iron (Males) : 60–160 µg/dL
It is recommended that each laboratory establish its
own normal range representing its patient population.
502 Concise Book of Medical Laboratory Technology: Methods and Interpretations Contents 35 mL 75 mL
L1: Iron cutter reagent 35 mL 75 mL
L2: Iron color reagent 2 mL 4 mL
S: Iron standard (100 µg/dL) 2 mL 2 mL
L1: TIBC saturating reagent 10 mL 20 mL
L2: TIBC precipitating reagent 1 g 2 g
Contents are stable at 2–8°C till the expiry mentioned on
Serum, free from hemolysis. Iron is reported to be stable in
Wavelength/filter : 570 nm (Hg 578 nm)/yellow
Pipette into clean dry test tubes labeled as blank (B),
standard (S), sample blank (SB) and test (T):
Iron buffer reagent (L1) 1.0 1.0 1.0 1.0
Iron color reagent (L2) 0.05 0.05 - 0.05
Mix well and incubate at RT for 5 minutes. Measure the
absorbances of the blank (Abs B), standard (Abs S), sample
blank (Abs SB) and test sample (Abs T) against DW.
Pipette into a clean dry test tube
Mix well and allow to stand at RT for 10 min and add
TIBC precipitating reagent (L2) Approx 50 mg
Mix well and allow to stand at RT for 10 minutes.
Centrifuge at 2500–3000 rpm for 10 minutes to obtain
a clear supernatant. Determine the iron content in the
supernatant as above mentioned iron assay.
Abs T- (Abs SB + Abs B) Iron in µg/dL = ________________________ × 100 Abs S – Abs B
Abs T – (Abs SB + Abs B) TIBC in µg/dL = _______________________ × 300 Abs S – Abs B
UIBC in µg/dL = TIBC in µg/dL – Iron in µg/dL
This procedure is linear upto 1000 µg/dL. If values exceed
this limit, dilute the sample with distilled water and repeat
the assay. Calculate the value using the proper dilution
Hemolysis interferes with the test as the hemoglobin
present in the RBCs has a very high iron content.
All glassware being used for the test should first be
rinsed with 1% or 0.1 N HCI and then with good quality
Reaction : End point + Interval : SB
Zero setting : Deionized Reagent
Delay time : — React slope : Increasing
Read time : — Linearity : 1000 µg/dL
b. Iron deficiency anemia due to hemorrhage
2. Decreased levels of TIBC are caused by
a. Children 2½ to 10 years of age
b. Pregnant women during the third trimester
2. Drugs that may cause increased TIBC are
The term trace elements refers to inorganic substances
which occur in concentration < 0.01% of the body mass,
i.e. in amounts < 10–6 g/g of body weight. They are divided
into essential and nonessential trace elements. In humans,
Cr, Co, Cu, Fe, l, Mn, Mo, Ni, Se, Zn belong to the former
category; Al, Ag, As, Au, Ba, Bi, Cs, Cd, Pb, Ti, and V belong
to the group of nonessential trace elements. The latter also
include elements without physiological functions as well
as toxic heavy metals. Magnesium, in a strict sense, is not
a trace element but is customarily considered to be one. In
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