Blood Glucose Estimation Test (M) Flashcards
True or False.
Glucose test is not routinely performed in the lab
False, because it is routinely performed in the lab
What clinical disorder can be diagnosed via glucose test?
Diabetes mellitus
What is the reference range for glucose test?
70 - 100 mg/dL
What is the unit for glucose test?
mg/dL
What are the sxs that can be used for glucose test?
1) Fasting venous plasma
2) Random Blood Sugar (RBS)
3) CSF
4) Synovial fluid
5) Serous fluid
6) Urine
What is the required time of fasting for fasting venous plasma sx?
8 - 10 hrs
What happens if the sx is unrefrigerated (there is a delay in testing)?
Decreases 7 mg/dL per hr
What happens if the sx is refrigerated (test can’t be done promptly)?
Decreases 2 mg/dL per hr
What is the result if whole blood is used as sx for glucose testing?
10 - 15% lower
The results if whole blood is used for glucose testing is lower than what?
Than serum and plasma
What is the percentage of the plasma concentrations of CSF?
60 - 70%
How to prevent the loss of glucose (in glucose test)?
Plasma glucose should be separated within an hour
What etubes should be used if glucose testing will be delayed?
Red, yellow, and gray tops
True or False.
Venous blood glucose is higher than capillary blood (RBS)
False, because venous blood glucose is lower than capillary blood (RBS)
How high or how low is venous blood glucose compared to capillary blood (RBS)?
It is lower than 7 mg/dL compared to capillary blood (RBS)
What tube is preferred to be used for glucose test?
Gray top
Why is gray top preferred to be used for glucose test?
Because it contains potassium oxalate / sodium fluoride
What is the action of enolase?
It inhibits glycolytic enzyme
2 mg of NaF per mL of blood prevents what?
It prevents glycolysis up to 48 hrs
What is the action of fluoride (sodium fluoride)?
It binds w/ magnesium w/c causes inhibition of enzyme enolase
What are the 2 types of methods of glucose estimation test?
1) Chemical method
2) Enzymatic method
What are the different methods under chemical method of glucose estimation test?
1) Oxidation - reduction
2) Hagedorn Jensen
3) Condensation method
What are the different methods under oxidation - reduction of glucose estimation test?
1) Folin-Wu
2) Nelson-Somogyi
3) Neocuprione (Neocupreine) method
4) Benedict’s method
What is the principle of oxidation - reduction?
The ability of glucose to directly reduce cupric ions to monovalent cuprous ions in the presence of heat
What are the chemical formulas for oxidation - reduction?
Heat: CuSo4 (cupric sulfide) + reducing substance -> Alkali: Cu2O (cuprous oxide) + oxidized substance -> color (blue / green to orange / red)
*heat and alkali rxns
What are the principles of Folin-Wu?
1) It uses tungstic acid to remove protein from serum
2) Measures sugar (FBS)
What are the principles of Nelson-Somogyi?
1) It uses zinc hydroxide
2) It measures true glucose (FBG)
What is the color of positive result of Neocuprione’s (Neocupreine’s) method?
(+) : yellow
What sx (and its volume) is used for Benedict’s test?
1 mL urine
What is the component of Benedict’s rgnt?
Copper sulfate
What is the chemical formula (or equation) of Folin-Wu?
Cu^+ + Phosphomolybdate acid -> phosphomolybdenum (blue)
What is the chemical formula (or equation) of Nelson-Somogyi?
Cu^+ + Arsenomolybdate acid -> arsenomolybdenum (blue)
What is the chemical formula (or equation) of Neocupreine method?
Cu^+ + neocuprine -> yellow to yellow-orange complex
What is the chemical formula (or equation) of Benedict’s method?
Copper sulfate (blue) + glucose + heat -> green -> yellow -> orange -> brick red
*color reactions depends on the intensity of the rxn