Salkowski test for cholesterol: Salkowski test is used to detect cholesterol in a solution. This test is named after a German biochemist Ernst Leopold Salkowski. Reagents: Cholesterol solution Chloroform Concentrated Sulphuric acid Procedure: Take 2 ml of cholesterol solution, in chloroform. Add 2 ml of concentrated sulphuric acid. Shake … [Read more...]
General tests for lipids – Its principle and procedure
General tests for lipids: Lipids comprise of very important group of organic substances present in plant and animal tissues. They have low melting point and are usually liquid at body temperature. They have high energy value. Lipids include fats, oils, steroids, waxes and other related compunds. They are insoluble in water but are soluble to varying degree in organic solvents … [Read more...]
ARGININE TEST (Test for Guanidine Group) Its principle & procedure
ARGININE TEST (Test for Guanidine Group): Significance: Arginine test is specific for Arginine and indicates the presence of guanidine group in the arginine molecule. Reagents: Protein solution 5% sodium hydroxide 1% alcoholic α-naphthol sodium hypobromite (NaOBr) PROCEDURE: Take 1 ml of original solution (protein solution) in a test tube. Add 1 ml … [Read more...]
Ammonium sulphate saturation test – Its principle, reagents and procedure
Ammonium sulphate saturation test: Significance: Ammonium sulphate saturation test is a confirmatory test. Half saturation (50% saturation) with ammonium sulphate will result in precipitation of globulins, whereas albumins are precipitated after full saturation (100% saturation) of the test sample with ammonium. Rragents: Ammonium sulphate crystals. Principle: Protein is … [Read more...]
To Estimate the percentage of glucose in urine by Benedict Quantitative Reagent (BQR)
To Estimate the percentage of glucose in urine by Benedict Quantitative Reagent (BQR): Apparatus: Burette titration flask pipette spirit lamp Chemical: synthetic urine containing 1gm glucose. Anhydrous sodium carbonate (for making solution more alkaline) Benedict quantitative reagent: which is composed of: Copper sulphate (Provide cupric … [Read more...]
Estimation of % percentage of titrable acidity of Gastric juice
Estimation of % percentage of titrable acidity of Gastric juice: Titrable Acidity: It is the amount of acid present in gastric juice. It is the amount of NaOH required to neutralize the acidity of gastric juice. Free acidity: It is the amount of free acid or HCL present in gastric juice. Normal range is 20-40% Combined Acidity: It is the amount of HCl that is bound … [Read more...]
All Protein Precipitation tests with Proper Procedures
PROTEIN PRECIPITATION TESTS: Protein gives protein precipitation tests because Proteins behave as cations in acid solutions and are precipitated with acid radicals to form insoluble salts. On the other hand, in alkaline solutions, they act as anions and are precipitated with heavy metals.By virtue of their sulphydryl (-SH) groups, they also act with salts of heavy … [Read more...]
Fehling’s test for reducing sugar
Fehling's test: Fehling's test is a specific test for reducing sugar. PRINCIPLE: The principle of fehling test is same to that of benedict's test. In the presence of reducing sugar, cuso4 gives cupric ion in an alkaline medium which reduces to cuprous ion. REAGENTS: Fehling’s A reagent: Solution A Copper sulfate solution (Cuso4) Fehling’s B reagent: Sodium-potassium … [Read more...]
Benedict’s test for reducing sugar
Benedict's test for reducing sugar: Benedict's test for reducing sugar is a particular test for reducing substances.This test can be: used as a rough quantitative test for the clinical evaluation. PRINCIPLE: In the presence of reducing sugar, cuso4 gives cupric ion in an alkaline medium which is reduced to cuprous ion cu+2 to form cuprous oxide cuo2, and different coloured … [Read more...]
Biochemistry mcqs for first year mbbs
Biochemistry MCQs for first year mbbs: Signaling in which a molecule is produced by one cell and acts on a neighboring target cell is known as A. Endocrine signaling Direct cell to cell signaling Paracrine signaling Autocrine signaling Transduction Steroids are derived from -Cholesterol -Phospholipid -Carbohydrate -Fatty … [Read more...]