Team:Yale/Interlab
From 2014.igem.org
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Fluorescence Activity Assay Protocol<br></strong> | Fluorescence Activity Assay Protocol<br></strong> | ||
- | + | <ol type="a"> <li>Grow 1 mL culture with selection marker and inducer overnight. <br> | |
- | + | <li> Transfer 150 µL culture into V-bottom plate. <br> | |
- | + | <li> Spin down cells in plate with plate spinner set to a temperature 24-25ºC for 4 minutes. The plate shaker will pellet the cells in the v-bottom well over 4 minutes. <br> | |
- | + | <li> Remove the supernatant and resuspend in 110 µL 1X PBS. <br> | |
- | + | <li> Transfer 110 µL of 1X PBS into clear bottom plate. <br> | |
- | + | <li> Transfer 10 µL of suspended cells into 100 µL fresh PBS in an adjacent well. Transfer 10 µL of second dilution into 90 µL of fresh PBS in an adjacent well. <br> | |
- | + | <li> Using Synergy H1 plate reader (BioTek, Winooski, VT), measure optical density and fluorescence. <br> | |
- | + | <li> Calculate expression of GFP <br></ol> | |
Revision as of 00:01, 17 October 2014
Interlab |
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Section I: Provenance and Release
a. Shake plate for 10 seconds. b. Measure optical density (OD) at 600 nm. c. Measure GFP fluorescence by exciting cells at 485 nm and detecting at 528 nm, with a bandpass of 4 nm on each side. 4. What method is used to determine whether to include or exclude each sample from the data set? Fluorescence readings that diverged from the other samples of the same type by more than 50% were excluded from the data set; however, no such issues were encountered. 5. What exactly were the controls that you used? During the growth phase of the cell cultures, the ancestral DH5α strain was also grown in LBmin and subject to the same antibiotic selection marker: kanamycin or chloramphenicol. Clear cultures after a day of incubation signified selection for the retention of the target plasmids. All cultures were seeded at the same time and allowed to grow for the same duration. 6. What quantities were measured? (e.g., red fluorescence, green fluorescence, optical density) Green fluorescence and optical density were measured. 7. How much time did it take to acquire each set of measurements? A time lapse of about five minutes occurred between each data set. The plates were seeded and incubated for 12 hours prior to measurement. 8. How much does it cost to acquire a set of measurements? We are only considering the cost of the non-renewable materials, which were consumed during our measurements. Below is a chart of the resources used: Reagent/Material Cost Gibson Assembly mix $31.40 LB and LB Plate $5.00 96 well plate $2.00 Total $38.40 9. What are the practical limits on the number or rate of measurements taken with this instrument and protocol? The DH5α strain used was not a robust strain, and its growing time greatly impeded construct creation and measurement. Section III: Measured Quantities 1. For each type of quantity measured (e.g., fluorescence, optical density), report on the following: 2. Units: i. What are the units of the measurement? Fluorescence was measured in relative fluorescence units (RFU). Optical Density was measured in absorbance units (AU). What is the equivalent unit expressed as a combination of the seven SI base units? (http://en.wikipedia.org/wiki/SI_base_unit) . Absorbance in AU is a ratio, and thus has no SI units. i. RFU is an arbitrary fluorescence unit and cannot be compared. 3. Precision: What is the range of possible measured values for this quantity, using your instrument as configured for these measurements? (e.g., a meter stick measures in the range of 0 to 1 meter) i. Dynamic range: 0-4 OD What are the significant figures for these measurement? (e.g., on a meter stick, it is common to measure to the nearest millimeter). i. 0.0001 OD Is the precision the same across the entire range? If not, how does it differ? i. Yes How did you determine these answers? i. Synergy H1 Specification Sheet 2. Accuracy: When was the instrument last calibrated? . March 2013 How was the instrument calibrated? . An accredited BioTek technician calibrated the machine against a known standard concentration gradient during initial setup of the machine. Section IV: Measurements 1. For each sample, report: the identity of the sample each quantity directly measured each quantity derived from measurements (e.g., fluorescence/OD) |