Table of Contents
What is the independent variable on the standard curve?
For a standard curve (i.e., a line graph that can used to find out the concentration of an unknown solution), the experimenter decides on the concentrations to be measured (independent variable) and the output from the spectrophotometer is the value for the dependent variable (called Optical Density or OD).
What is the maltose standard curve?
The standard curve for maltose is usually constructed using 3, 5-Dinitro salicylic acid (DNS) as the reagent. Maltose reduces the pale yellow coloured alkaline 3,5-Dinitro salicylic acid (DNS) to the orange- red coloured, 3 amino,5 nitro salicylic acid. The plot thus obtained is called a standard maltose curve.
What is the purpose of preparing a standard curve?
A standard curve is a tool that allows us to estimate the DNA concentration of unknown samples by comparing them to standards with known DNA concentrations.
Which variable is the dependent variable absorbance or concentration?
According to the Beer-Lambert law, concentration is the dependent variable and absorbance is the independent variable. Thus, when graphing to produce a standard curve, concentration will be placed on the X-axis and absorbance will be placed on the Y-axis.
Is concentration a dependent variable?
The dependent variable is often the quantity you want to measure; it the result of the experiment or test. The dependent variable is the resulting hemoglobin concentration.
What is the DNSA method?
1. DNSA Method: Principle: 3, 5-Dinitrosalicylic acid (DNSA) is used extensively in biochemistry for the estimation of reducing sugars. This involves the oxidation of the aldehyde functional group (in glucose) and the ketone functional group (in fructose).
How is a calibration curve constructed?
A calibration curve is created by first preparing a set of standard solutions with known concentrations of the analyte. The instrument response is measured for each, and plotted vs. concentration of the standard solution. A set of standard solutions is used to prepare the calibration curve.
What is the purpose of a calibration curve in spectrophotometry?
A calibration curve is a way to identify the concentration of an unknown substance. These curves use data points of known substances at varying concentrations, and researchers or developers can use these curves to find where an unknown substance plots.
Is absorbance a dependent variable?
Absorbance, the dependent variable, is placed on the y-axis (the vertical axis). Concentration, the independent variable (because it was set by you when setting up the experiment), is graphed on the x-axis. The absorbance (or y) is what you measure from your unknown.
How do you remember independent and dependent variables?
Many people have trouble remembering which is the independent variable and which is the dependent variable. An easy way to remember is to insert the names of the two variables you are using in this sentence in they way that makes the most sense.
How to make maltose standard curve by DNS method?
To this solution add about 30g of sodium potassium tartarate tetrahydrate in small lots, the solution turns milky yellow in colour. Then add 20ml of 2N NaOH, which turns the solution to transparent orange yellow colour. The final volume is made to 100 ml with the distilled water.
What kind of reagents are used for maltose standard curve?
Preparation of Reagents: 3,5-dinitrosalicylic acid
How much maltose is in a standard solution?
Maltose working solution : 180mg of maltose is weighed and made up to 100ml with distilled water. Pipette out standard maltose solution in the range of 0.2, 0.4, 0.6, 0.8 and 1 ml, into 5 separate test tubes. A test tube containing a blank solution is also prepared.
How much maltose is in a test tube?
Pipette out standard maltose solution in the range of 0.2, 0.4, 0.6, 0.8 and 1 ml, into 5 separate test tubes. A test tube containing a blank solution is also prepared. Using distilled water, bring the volume up to 2ml in each test tube, including the test tube containing the blank solution.