Blood Urea Estimation nitrogen containing.pdf

Urea is a nitrogenous compound,nitrogen

1. TABLE 27.8: Common tests to assess kidney function
Constituent
Urea
Creatinine
Uric acid
Sodium
Potassium
Calcium
Blood level or Urine
excretion
B= 15-40 mg/dL
U= 15-30 g/day
B=0.7-1.4 mg/dL(M)
B= 0.4-1.3 mg/dL(F)
U= 1-2 g/day
B=3-7 mg/dL (M)
B= 2-5 mg/dL (F)
U=0.5-0.8 g/day
B=135-142 mmol/L
B=3.5-5 mmol/L
B=9-11 mg/dL
Factors affecting urinary
excretion
Dietary proteins,
protein catabolism, Renal
blood flow
GFR, tubular secretion, age,
sex, muscle mass
Purine catabolism, tubular
excretion
State of hydration, dietary
sodium, renal function
Dietary potassium, acid
base balance, renal function
Dietary calcium, PTH,
calcitonin, renal function

2. Blood Urea
>Normal value is 10 40 mg/dL.
>Urea is the end-product of protein metabolism.
>Increased Blood Urea
" Serum urea is Increased in all forms of kidney diseases.
" In the early stages of nephrosis, serum urea may be
normal, but in late stages, serum urea increases along
with decreasing renal function.
>Decreased Blood Urea
"Urea concentration in serum may be low in late
pregnancy, in short-term starvatlon, In a diet grossly
deficlent in proteins, and in hepatic failure.

3. Methods of Serum Urea Estim:
1. Enzymatic Method
a) Nessler's method
b) Berthelot reaction
c) Glutamate Dehydrogenase Method
2. Non-Enzymatic Method
a) Dlacetyl-Monoxime method (DAM Method).

4. BLOOD UREA ESTIMATION
Bl: 11.21
" AIM-Estimation of Blood Urea by Diacetyl
Monoxime method (DAM Method).

5. " REAGENTS
1. Acid reagent
(a) Ferric chloride in Ortho Phosphoric Acid
(b) Conc H,SO.
2. Colour reagent
a) Diacetyl monoxime
b) Thiosemicarbazide
3. Standard Urea-30mg/100ml

6. "PRINCIPLE-Urea reacts with diacetyl rnonoxime in a
strongly acid medium when heated to form a yellow
colored complex. Thíosemiícarbazíde is used as a catalyst,
and Ferric chloride (FeCl, ) intensifies the color. This
reaction is intensified by the presence of ferric íons and
thíosemlcarbazíde and then the color produced Is red/pink
whlch ís more linear with a concentration of urea than the
yellow color produced in absence of thiosemicarbazide.
This method covers the range of 300 mg/10oml, within this
range O.D. is linear with concentratíon.

7. Acid
" diacetyl monoxime --
" Diacetyl t urea
filter-green -S40)
Medium
diacetyl + hydroxylamine
-Diazine (color -pink/red,

8. " 3 test tube is taken and marked as B, s, T.
3ml of acid reagent and 3ml of colour reagent is taken in
all the test tube. Now in 'B' test tube 0.1 ml of distilled
water, in S test tube 0.1 ml of standard solution, and in
T test tube 0.1ml of serum is added. Now all the test
tubes are kept in boiling water bath for 10 min.
After 10 min all the test tubes are taken out and cooled.
Now reading of all test tube is taken with photoelectric
colorimeter using green filter (520nm).

9. " PROCEDURE
Acid Reagent
Colour Reagent
Dbtilled water
Standard solut lan
Test
BLANK
3 mi
3 ml
0.1 ml
STANDARD
3 ml
3 ml
0.1 ml
TEST
3 m
3 ml
01 ml

10. " CALCULATION:
Amount of urea in given sample =
O.D. of test-O.D of blankx conc. of standard
O.D. of std.-O.D. of blank

11. " READING:
O.D. of Blank =
0.D. of standard =
O.D. of test =
Conc. of standard = 30mg/100ml

12. "RESULT
The amount of urea in the given
sample is .... mg/dl.