CHEM EXAMINATION-Protein, Glucose

Methods for protein determination

Heat and Acetic acid

Sulfosalicylic acid

Reagent strip

Protein reagent strip principle

Protein Error of Indicators

Protein reagent strip Indicator:

tetrabromphenol blue (Multistix) or

3’, 3”, 5’, 5”- tetrachlorophenol-3, 4, 5, 6-tetrabromosulfonphthalein (Chemstrip)

Protein reagent strip Reaction is buffered at

pH 3 using citrate

Protein is correlated with:

Blood, Nitrite, Leukocytes and Microscopic examination

presence of any sugar in urine

Mellituria

presence of any reducing sugar in urine

Glycosuria

presence of glucose in urine

Glucosuria

most frequently assayed chemical/substance in urine

Glucose

Normal glucose in urine

15 mg/dL

Glucose Renal threshold is

160 to 180 mg/dL

Amount in the glomerular filtrate exceeds reabsorptive capacity

Hyperglycemia

T/F Reagent Strips are Specific to glucose

True

Glucose Reagent strip principle

Double Sequential Enzyme

Glucose Reagent strip Sensitivity:

Clinistix:

Multistix:

Chemstrip:

100 mg/dL

75 to 125 mg/dL

40 mg/dL

In Glucose Reagent strip what brand is more Sensitive

Chemstrip

Glucose reagent strip interferences that causes False positive

contamination with peroxide or strong oxidizing agents

Glucose reagent strip interferences that causes False negative

high levels of ascorbic acid, unpreserved specimens, increased ketones, high specific gravity, low temperature

Laboratory Detection of Sugar/Glucose

Reagent strip

Copper reduction / Benedicts tests

Clinitest

General test for glucose and other reducing substances

Copper Reduction Tests

Principle: ability of glucose and other substances to reduce copper sulfate to cuprous oxide in the presence of heat and alkali

Copper Reduction Tests

Copper Reduction Tests interferences that causes False positive:

drugs and other reducing substances

Copper Reduction Tests interferences that causes False negative:

rapid glycolysis

More convenient method for sugar determination

Clinitest

Clinitest Sensitivity

150 mg/dL