DETERMINATION
OF GLUCOSE IN
BODY FLUIDS
METHODS
CHEMICAL
METHODS
ENZYMATIC
METHODS
Benedict reaction
CHEMICAL METHODS
 Oxidation
- Reduction Methods
* Folin – Wu
* Somogyi - Nelson
 Condansation
Methods
* orto - Toluidine
Folin - Wu
Glucose + Cu2+
Gloconate + Cu+
pH > 7 , heat
Cu+ + phosphomolybdate
blue
molybdenium
complex
λ = 660 nm
Somogyi - Nelson
Glucose + Cu2+
Gloconate + Cu+
pH > 7 , heat
Cu+ + arsenomolybdate
blue
molybdenium
complex
λ = 660 nm
o - Toluidine Method
o - Toluidine + Glucose
Glycosylamine
NH2
pH < 7 , heat
CH3
Schiff Base
(aniline - benzidine)
λ = 630 nm
color complex
Interference
 Bilirobin
 Galactose
 Mannose
 Hemoglobin

Glucose oxidase
– Inhibited by

High concentrations of uric acid, ascorbic acid,
bilirubin, glutathione, creatinine. Lcysteine, L-dopa. Dopamine, methyldopa
and citric acid
Enzymatic Methods
 Glucose
Oxidase
 Hexokinase
 Glucose
dehydrogenase
Glucose Oxidase
mutarotase
α -D-Glucose
β-D-Glucose
O2
glucose oxidase
Gluconic acid + H2O2
peroxidase
H2O2 + chromogen
(o-dianisidine)
color complex
+ H2O
(phenylamine)
λ = 520 nm
Hexokinase method
H
Glucose dehydrogenase
method
Clinical Significance
F.B.S (Fasting Blood Suger)
 Fasting
12 - 14 hours
 Normal Range 70 - 110 mg/dL
decrease
hypoglycemia
increase
hyperglycemia
Diagnosis of Pre-Diabetes
and Diabetes Mellitus
Hyperglycemia
 FBS
> 140 mg/dL
 Primary (Diabetes Mellitus)
* IDDM (type I)
* NIDDM (type II)
Insulin Dependent Diabetes Mellitus
(IDDM)
Absolute deficiency of insulin
 make up about 10% of all patients with D.M.
 IDDM persent at an early age (usually before
30)
 Clinical signs :
blood glocose
insulin
ketosis
loss of body weight

Noninsulin Dependent
Diabetes Mellitus (NIDDM)
Deficiency of insulin receptor
 Patients are commonly obese
 NIDDM is the most common from of D.M. ( 8090%)
 usually first present at an age over 40
 Clinical signs : blood glucose
insulin
osmotic diurocis
dehydration

Characteristics ofType 1 and Type 2 Diabetes Mellitus
Secondary hyperglycemia
 Pancratectomy
 acromegaly
 Cushing’s
syndrome
 glucagonoma
Hypoglycemia
 Adult
< 45 - 50 mg/dL in fasting
 infant
* preterm < 25 mg/dL
* fullterm < 35 mg/dL
Causes of hypoglycemia
 Insulinoma
(islet cell tumors)
 Glycogen Storage Diseases (GSD)
 Addison’s disease
OGTT
Fasting
0.5
1
2
3
80 mg/dL
155 mg/dL
165 mg/dL
140 mg/dL
80 mg/dL
Oral Glucose Tolerance Tests
(OGTT)
OGTT curve
2hpp (two hours postprandial
plasma glucose)

2hpp (two hours postprandial
plasma glucose) used to screen for
diabetes mellitus and to monitor
glucose control
Blank
Standard
Test
Water
0.05 ml
-
-
Standard
100
mg/dL
Test
-
0.05 ml
-
-
-
0.05 ml
Reagent
3 ml
3 ml
3 ml
 Put
10 minute in boil water bath
 read
Ct
at 630 nm
=
At
Ast
Cst
‫هموگلوبين گليكوزيله‬
Hormonal regulation of blood glucose.
Response of plasma insulin to glucose stimulation
Criteria for the diagnosis of diabetes mellitus
Screening and diagnosis of gestational diabetes mellitus