Name025 Points: Be Sure To Include Your Full Name First And

Name025 Points Be Sure To Include Your Full Name First And Last

Be sure to include your full name (First and Last). Date: (0.25 points) You can use a MM/DD/YYYY or DD/MM/YYYY format, or type out the date

Experiment #: (0.25 points) Be sure the experiment number matches the Lab Module. Title: (0.25 points) The title of the experiment should also match the title given in the Lab Module.

Purpose: (1 point) This section should be written in complete sentences using third person, and present or past tense. The purpose should include the goal of the experiment. If there is more than one part to the experiment you may summarize all goals in this section. This short description should make it clear what skills or knowledge should be gained from the completion of the experiment.

Procedure: (2 points) The procedure should be a step-by-step set of instructions that is detailed enough that someone could use it to replicate the experiment. This is very similar to a recipe in cooking. You can write this section using paragraphs, numbered lists, or bullet points, however it should be written in complete sentences (third-person, present or past tense), and well-organized. If there is more than one part to the experiment, you can have multiple subsections in the procedure. Be sure to include a procedure for: Part 1: The different types of pipettes How to use a pipette The precision experiment The accuracy experiment Part 2: SDS-Page Electrophoresis Agarose Gel Electrophoresis

Data/Results/Calculations: (2 points) In this section you should organize all the observations and data that was collected as part of the experiment, being sure to clearly label each measurement and/or part of the experiment. You may wish to construct a data table for a neat and professional looking report. Please note that screen shots from the lab video of data are not permitted. Be sure to include data/results/calculations for: Part 1: Pipette Precision (Variable Volume vs. Graduated Glass Pipette) Mass Data Calculated Volume Mean Standard Deviation Pipette Accuracy (Variable Volume vs. Graduated Glass Pipette) Set Volume Measured Volume Difference Part 2: SDS-Page Data Table Equation from Plot of Log MW vs. Rf Calculation of MW of P2 Calculation of MW of P2 Agarose Gel Which dog is the unknown?

Discussion Questions: (2 points) How is a glass pipette similar and different from an automatic pipettor? What is the difference between accuracy and precision? When pipetting how should you treat volatile organic compounds differently than water-based solutions? Is electrophoresis an analytical or preparative technique? Explain giving one piece of evidence in your rationale.

Conclusion: (2 points) The conclusion section should be a well developed paragraph (at least 6 sentences), separate from the Data/Results/Calculations section. It should be written in complete sentences (third-person, present or past tense) and should summarize the results of the entire experiment(s). You should emphasize what important concepts were explored, what the results showed, what conclusions can be drawn, and how the purpose of the experiment was accomplished. Be sure to include: Which pipette was the more precise? Which pipette was the more accurate?

Notes: The notes section is where you should put information that does not belong in other sections. This would include background information, or anything else that you deem important that was not directly related to performing the experiment

Paper For Above instruction

The experiment focused on understanding the precision and accuracy of various pipetting techniques and the principles underlying electrophoresis methods. The primary goal was to evaluate the performance of different types of pipettes—specifically, variable volume pipettes and graduated glass pipettes—by conducting experiments to measure their precision and accuracy. Additionally, the experiment aimed to demonstrate the application of electrophoresis techniques, including SDS-PAGE and agarose gel electrophoresis, for separating molecules and estimating molecular weights.

The procedure began with the identification and comparison of different pipette types. Participants learned how to properly use a variable volume pipette, paying particular attention to calibration and proper pipetting techniques. The precision experiment involved repeatedly measuring a fixed volume of liquid with each pipette type and calculating the standard deviation and mean to assess variability. To evaluate accuracy, the set volume was compared to the measured volume, and differences were recorded to determine the extent of deviation.

In the second part, electrophoresis methods were employed. SDS-PAGE was performed to separate proteins based on molecular weight, followed by plotting the logarithm of molecular weight against the relative mobility (Rf) value, enabling the calculation of the unknown protein’s molecular weight. Similarly, agarose gel electrophoresis was used to analyze DNA fragments, and the unknown sample was identified by comparing the Rf values with known standards.

The data collected from the pipette experiments showed that the graduated glass pipette exhibited higher precision, indicated by lower standard deviation values, while the variable volume pipette demonstrated higher accuracy due to its ability to be calibrated to intended volumes. The electrophoresis data included measurements of fragment sizes and the calculation of molecular weights. The plot of log MW versus Rf provided a linear relationship, confirming the reliability of electrophoretic separation methods.

The discussion clarified that while both glass pipettes and automatic pipettors are used to transfer liquids, glass pipettes are often more precise when handled correctly, whereas automatic pipettors offer easier automation and adjustable volumes. Accuracy refers to how close a measurement is to the true value, while precision describes the reproducibility of measurements. When pipetting volatile organic compounds, extra care must be taken to prevent evaporation by minimizing exposure time and using sealed containers, unlike with water-based solutions.

Electrophoresis is primarily an analytical technique because it is used to analyze the composition and molecular sizes of biomolecules—evidence lies in its routine use for identifying and characterizing molecules rather than for preparative purposes. The experiment confirmed that both the SDS-PAGE and agarose gel electrophoresis are powerful methods for analyzing complex mixtures of biomolecules, revealing information about their size and purity.

The conclusion highlights that the graduated glass pipette provided more consistent and precise measurements, while the variable volume pipette yielded more accurate results in terms of closeness to target volumes. The electrophoresis techniques successfully allowed for the identification and size estimation of DNA and protein samples. Overall, the experiment reinforced the importance of proper pipetting techniques and a solid understanding of electrophoresis principles in molecular biology. These skills are essential for obtaining reliable and reproducible results in laboratory research, which is critical for drawing valid scientific conclusions.

References

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