Pengujian Kadar Protein dengan Metode Lowry

Summary

In this practical experiment, the process begins with preparing essential laboratory equipment, such as test tubes, pipettes, beakers, and cuvettes. The main focus is on isolating egg white protein, which is first extracted and diluted with distilled water. After several steps of dilution and mixing, the sample is incubated and subjected to specific treatments with reagents. Following incubation, the sample is measured using a spectrophotometer to analyze the protein concentration at a wavelength of 666 nm. This methodical process allows for precise protein quantification in a laboratory setting.

Takeaways

• 😀 The tools used in the experiment include a reaction tube, pipette, glass beaker, and cuvette.
• 😀 The first step involves preparing the egg, focusing on separating the egg white from the shell and weighing it.
• 😀 1 gram of egg white is then dissolved in 100 mL of aquades (water).
• 😀 The dissolved egg white is mixed and diluted, followed by taking 0.5 mL of the solution and further diluting it to 10 mL.
• 😀 The solution is then further diluted using aquades to achieve the required concentration.
• 😀 A dilution series is created for the protein stock solution.
• 😀 Aquades is added to each measuring flask to adjust the volume to 10 mL for each sample.
• 😀 The solution is vortexed to ensure it is mixed thoroughly.
• 😀 The mixture is incubated for 10 minutes, followed by the addition of a reagent.
• 😀 After vortexing again to homogenize the solution, it is incubated for an additional 30 minutes.
• 😀 The sample is then measured using a spectrophotometer at a wavelength of 666 nm, starting with the blank sample to calibrate the instrument.

Q & A

What are the primary tools and materials used in the experiment described in the script?

The primary tools used in the experiment are a test tube, pipette, glass beaker, and cuvette. The materials include an egg, protein powder, reagents, and aquades (distilled water).

What is the first step in the preparation process of the egg for the experiment?

The first step is to crack the egg and separate the egg white from the yolk, then weigh the egg white until it reaches one gram.

How is the egg white diluted for the experiment?

The egg white is diluted by mixing one gram of it with 100 milliliters of aquades (distilled water).

How is the concentration of the egg white solution adjusted after the initial dilution?

After the initial dilution, 0.5 milliliters of the egg white solution is taken and further diluted in a graduated cylinder until the volume reaches 10 milliliters.

What is done after the dilution of the egg white solution?

After dilution, additional aquades are added to ensure the solution reaches the required volume, and a dilution series is made for the protein stock.

What step follows the creation of the dilution series for the protein stock?

After preparing the dilution series, aquades are added to each graduated cylinder to ensure the volume of each solution reaches exactly 10 milliliters.

What happens after the solutions are prepared in the graduated cylinders?

The prepared solutions are transferred to test tubes. Reagents are then added to each test tube, whether for sample or standard curve measurement.

What is the purpose of vortexing the solution?

Vortexing the solution ensures that the mixture becomes homogeneous, allowing for proper reaction and accurate measurement.

How long is the solution incubated after vortexing?

The solution is incubated for 10 minutes after vortexing, followed by the addition of reagents and a further 30-minute incubation.

What is the next step after the incubation period?

After the incubation, the measurement is performed using a spectrophotometer at a wavelength of 666 nm. The blank is first measured to calibrate the spectrophotometer before measuring the samples.