Microscopy report outline

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20.309: Biological Instrumentation and Measurement

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General guidelines

  • Submit one paper per group.
  • Bulleted list or outline format is encouraged
  • Report numerical results properly
    • Indicate the units of measurement
    • Include the sample size and an appropriate measure of variability, such as a range, standard deviation, or standard error
    • Use the abbreviation "s.d." for standard deviation and "s.e.m." for standard error after the "±"
    • For example: 1.21 ± 0.03 GW (±s.d., n=42)
  • Explain how you analyzed the data
    • Summarize the algorithm used for all calculations and analyses
    • Provide an outline of each MATLAB (or other language) function or script you used
    • Put the complete code in an appendix
    • Indicate the source of any code you did not write yourself
  • Discuss your results
    • Compare your results to theoretical predictions, reported values from literature, or other students' results
    • Explain any factors that may have affected your results
    • Describe what you would do differently if you had the opportunity to do the experiment again.
  • Provide a detailed, correct, and comprehensive discussion of error sources for each measurement
    • Is the resulting error random or systematic?
    • If the error is systematic, can you determine the sign of the effect and its approximate magnitude?
    • How could the error be reduced?
  • Present data properly
    • Images should include a scale bar
    • Plots should have a clear title; axes should be labeled with units; use a plot legend when appropriate
  • See the Lab report general guidelines.
  • The report should be in PDF format, submitted electronically to Stellar in advance of the deadline.
  • The report title should contain the last name of each of your group members.

Part 1: Microscope construction and bright field characterization

Microscope documentation and design

  • Microscope block diagram, including all optical elements and relevant distances. It is unnecessary to document the details of the mechanical construction.
  • Design calculations and considerations
  • Photograph of your setup (optional, but nice)

Microscope characterization

  • Characterize the transmitted bright field performance of the microscope
  • Provide calculations of magnification, images used for that purpose, and comment on the accuracy of your calculations as described below.
  • After calibration, measure an appropriate size of microspheres for each of the objectives and comment on the mean and uncertainty of your measurements
  • Magnification and field of view
    • Include a table with the following values for the 10X, 40X, and 100X objectives:
      • Theoretical resolution
      • Actual magnification by multiple measures (Air Force Target, Ronchi Ruling)1
      • Calculate the actual field of view (FOV)1
    • Comment on and quantify the uncertainty of these measurements. How can you/did you improve it?
    • Provide a few example transilluminated pictures from each objective (there is no need to provide all)

Part 2: Fluorescence microscopy characterization

  • Characterize the fluorescent imaging performance of your microscope
  • Provide your fluorescent reference image(s) (as an image or a surface plot (see surf command in Matlab) and provide a cross-section across the diagonal (see improfile command in Matlab)
  • Correct all images for nonuniform illumination (the flat field correction). Compare to the uncorrected versions in two or three cases.
  • Describe your flat-field correction procedure from recording the reference image through applying the correction.
  • Also provide histograms of at least one original and corrected image pair
  • Comment on your corrections and relate your results to your choices during beam expander design and construction

Part 3: Resolution, Brownian motion and stability test

Summary

  • Image PSF beads and calculate resolution
  • Track microspheres suspended in a solvent and measure microscope stability
  • Estimate diffusion coefficients; calculate viscosities from those estimates
  • Comment on/quantify uncertainty. How can you/did you improve it?

Details

  • Provide a bullet point outline of image processing methodology
  • Report measured resolution of 40X (or 100X) objective1
    • Provide a sample of the images used for resolution estimation (overlay the fit – see plotgaussfit command)
    • Provide a table with measured estimates of FWHM resolution by Gaussian fitting1 for the 40x objective
    • Bullet point outline of data analysis methodology
    • Comment on estimated versus theoretical value
  • Stability
    • Provide X-Y plots of sum and difference tracks for fixed particles.
    • MSD versus time interval for sum and difference tracks1
    • Bullet point outline of data analysis methodology
    • Comments on observed vs. expected data trend
  • Viscosity samples
  • Estimate diffusion coefficient, viscosity and other mechanical properties for each sample
  • Comment on results, specifically how they are influenced by microscope stability, resolution,
  • Comment extensively on sources of error and approaches to minimize them, both utilized and proposed
  • Bullet point outline of all calculation and data processing steps

Part 4: 3T3 experiments

  • Report your findings on 3T3 actin visualization and cytoplasm microrheology
  • Quantify your investigations of the actin structure.
  • Quantify your investigations of the cytoplasm/cytoskeleton microrheology.
  • Comment on/quantify uncertainty. How can you/did you improve it?



1Remember to include uncertainty and a discussion of error sources for all numerical results.