What is the copper reduction test used for?
The classic Benedict’s copper reduction reaction was an early method used to detect glucose in urine. The test is based on the principle that substances that reduce copper sulfate to cuprous oxide in the presence of alkali and heat will produce a color change, which confirms the presence of glucose.
What does a positive Clinitest mean?
The CLINITEST hCG test When the urine hCG level is ≥ 25 mIU/mL, it indicates a positive result. When the urine hCG level is ≤ 5 mIU/mL, it indicates a negative result. When the urine hCG level is between 5 and 25 mIU/mL, it indicates a borderline result.
What is another name for the copper reduction test?
Benedict’s reagent (often called Benedict’s qualitative solution or Benedict’s solution) is a chemical reagent and complex mixture of sodium carbonate, sodium citrate, and copper(II) sulfate pentahydrate. It is often used in place of Fehling’s solution to detect the presence of reducing sugars.
What are the reducing substances in urine?
Reducing substances are not normally present in urine and faeces. This test will detect the presence of reducing sugars, eg glucose, lactose, maltose, fructose and galactose. The test is normally carried out on children who fail to thrive and who could be lactose intolerant.
Why does glucose give a positive Benedict test?
The concentration of aldehyde at any given time is small (<1%), but long-lived enough to be trapped with the right reagent. This means that glucose will give a positive test with Benedicts’ reagent, Fehlings solution, or the Tollens test, and the aldehyde will be oxidized to a carboxylic acid. Voila!
What does ketones in urine mean?
If your cells don’t get enough glucose, your body burns fat for energy instead. This produces a substance called ketones, which can show up in your blood and urine. High ketone levels in urine may indicate diabetic ketoacidosis (DKA), a complication of diabetes that can lead to a coma or even death.
Why would a Clinitest test be positive and the dipstick negative?
Clinitest was usually run as a reflex test on urine samples with a negative dipstick glucose result. A negative dipstick glucose assay and a positive reducing test suggest that some substance other than glucose is present in the urine. These sugars include galactose, lactose, and fructose.
What is a Clinitest?
Clinitest tablets are used to test how much sugar (glucose) there is in a person’s urine. Poisoning occurs from swallowing these tablets. Clinitest tablets used to be used to check how well a person’s diabetes was being controlled. These tablets are rarely used today.
What can cause false positive blood readings on a urinary dipstick?
Dehydration and exercise will give a false-positive dipstick for true hematuria, and vitamin C (which blocks peroxidase activity), captopril use, a pH less than 5.1, and proteinuria may produce a false-negative dipstick analysis for blood.
What is meant by reducing substances?
1. Definition. Reducing substances comprise all the sugars exhibiting ketonic and aldehydic functions and are determined by their reducing action on an alkaline solution of a copper salt.
What reducing sugar is usually tested in urinalysis?
Although glucose is the sugar most commonly tested for in urine, normal human urine can contain small amounts of galactose, lactose, fructose, xylose, and other pentoses. Galactosuria, an abnormal amount of galactose in the urine, occurs in infants with a congenital metabolic defect.
How do you test for glucose with copper reduction reaction?
Copper Reduction Reaction. The classic Benedict’s copper reduction reaction was an early method used to detect glucose in urine. The test is based on the principle that substances that reduce copper sulfate to cuprous oxide in the presence of alkali and heat will produce a color change, which confirms the presence of glucose.
What reducing substances are detected in urine?
However, other reducing sugars are also detected, as are other reducing substances, such as ascorbic acid, certain drug metabolites, and some antibiotics. Current tablet methods use the classic Benedict’s copper reduction principle to detect reducing substances in urine.
What is the Benedict’s Copper reduction reaction?
Access the complete course and earn ASCLS P.A.C.E.-approved continuing education credits by subscribing online. The classic Benedict’s copper reduction reaction was an early method used to detect glucose in urine.
What does a microscope analysis of a urine specimen yield?
Microscope analysis of a urine specimen yields a moderate amount of red blood cells in spite of a negative result for occult blood using a reagent strip. The technologist should determine if this patient has taken: