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OUR TEAM
LAB 5 WRITE-UP
SYBR Green Dye
The SYBR Green Dye is a small molecular dye that, when in the presence of dsDNA, will become very fluorescent but when in the presence of water or ssDNA, will not become very fluorescent.
Single-Drop Fluorimeter
The single-drop fluorimeter is a black box with a cradle on top for the glass slide that will have a drop on it. Towards the front of the cradle there is a blue LED light that can be toggled on or off with a switch.
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Image 1 shows the top view of the fluorimeter.
How the Fluorescence Technique Works
Fluorescence microscopy has been used in order to highlight parts of the lab experiment that is being recorded. The method in this lab has been used in order to test the concentration of DNA within a sample. We used SYBR green for the experiment. The SYBR green in the sample binds to the sample DNA and, once bound, fluoresces giving off green light when illuminated by blue light. The green light that is emmited from the drop of DNA/SYBR green is indicative of the concentration of DNA in the sample. The reason why we use a blue LED is because it intensified the florescence event. A lab should use SYBR green to dye the DNA because it is environmentally friendly and also other dyes (that are soluble in water) would not become florescent when the LED light hits the sample.
Procedure
Smart Phone Camera Settings
- Type of Smartphone: iPhone 4
- Flash: No flash
- ISO setting: 800
- White Balance: Auto
- Exposure: Highest
- Saturation: Highest
- Contrast: Lowest
Calibration
To set up the system, place the smartphone on the cradle at a right angle. Adjust the fluorimeter height using plastic trays so that the camera takes a picture of the drop sideways. Change the distance of the smart phone from the fluorimeter so that the phone can take a clear image.
Image 2 shows the basic set up of the system.
* Distance between the smart phone cradle and drop = 11.52 cm
Solutions Used for Calibration [Instructions: See worksheet page 6.]
Placing Samples onto the Fluorimeter
- Place a blank side into the Fluorimeter
- Turn on the blue led "excitation light"
- Place 80 microliters of SYBR Green dye in the middle of the first two rows of the slide
- Place 80 microliters of the calf thymus on top of the SYBR Green dye
- Place the camera in the cradle so it is able to take a picture of the side of the drop with the timer and flash on
- Record the distance between the phone and the drop
- Take picture
Data Analysis
Representative Images of Samples

Image 3 shows the drop without DNA.

Image 4 shows the drop with DNA.
Image J Values for All Samples
Calibration
| Final DNA concentration in SYBR Green I solution (µg/mL)
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AREA
|
Mean Pixel Value
|
RAWINTDEN OF THE DROP
|
RAWINTDEN OF THE BACKGROUND
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| 1. 2.5 |
160 |
150.369 |
24059 |
1194
|
| 2. 2.5 |
826 |
230.78 |
190624 |
10613
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| 3. 2.5 |
860 |
235.206 |
202277 |
30313
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| 4. 1.0 |
471 |
171.968 |
80997 |
10094
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| 5. 1.0 |
502 |
165.169 |
82915 |
14455
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| 6. 1.0 |
474 |
176.766 |
83787 |
19964
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| 7. 0.5 |
615 |
119.208 |
73313 |
20552
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| 8. 0.5 |
816 |
116.776 |
95289 |
9187
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| 9. 0.5 |
651 |
123.55 |
80431 |
5511
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| 10. 0.25 |
428 |
74.701 |
31972 |
12575
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| 11. 0.25 |
521 |
76.896 |
40063 |
17322
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| 12. 0.25 |
540 |
82.072 |
44319 |
8081
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| 13. 0.125 |
384 |
51.302 |
19700 |
6656
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| 14. 0.125 |
406 |
48.613 |
19737 |
9009
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| 15. 0.125 |
412 |
53.32 |
21968 |
5425
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| 16. 0.0 |
512 |
22.373 |
11455 |
4725
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| 17. 0.0 |
474 |
22.532 |
10680 |
9211
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| 18. 0.0 |
471 |
22.541 |
10617 |
6465
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PCR Products
| PCR Product TUBE LABEL
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Volume of the DILUTED PCR Product solution (µL)
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Volume of the SYBR GREEN I Dye solution (µL)
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'
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INTDENS VALUES BASED ON 3 SEPARATE DROP MEASUREMENTS'
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'
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AVERAGE INTDENS VALUE
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|
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| 1. 8PC |
80 |
80 |
182084 |
152527 |
153601 |
162737
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| 2. 8λ1 |
80 |
80 |
59485 |
40356 |
39911 |
46584
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| 3. 8λ2 |
80 |
80 |
48082 |
56735 |
64465 |
56427
|
| 4. 8λ3 |
80 |
80 |
50058 |
49921 |
50493 |
50157
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| 5. 8NC |
80 |
80 |
56801 |
68031 |
60370 |
61734
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| 6. 8θ1 |
80 |
80 |
238412 |
217854 |
188389 |
214885
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| 7. 8θ2 |
80 |
80 |
231847 |
235892 |
212734 |
226824
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| 8. 8θ3 |
80 |
80 |
220105 |
153560 |
158086 |
177250
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Concentration of PCR Product (DNA)
| PCR Product TUBE LABEL
|
Volume of the DILUTED PCR Product solution (µL)
|
Volume of the SYBR GREEN I Dye solution (µL)
|
INTDENS VALUES BASED ON 3 SEPARATE DROP MEASUREMENTS
|
'
|
'
|
AVERAGE INTDENS VALUE
|
|
|
|
|
|
|
|
| 1. 8PC |
80 |
80 |
182084 |
152527 |
153601 |
162737
|
| 2. 8λ1 |
80 |
80 |
59485 |
40356 |
39911 |
46584
|
| 3. 8λ2 |
80 |
80 |
48082 |
56735 |
64465 |
56427
|
| 4. 8λ3 |
80 |
80 |
50058 |
49921 |
50493 |
50157
|
| 5. 8NC |
80 |
80 |
56801 |
68031 |
60370 |
61734
|
| 6. 8θ1 |
80 |
80 |
238412 |
217854 |
188389 |
214885
|
| 7. 8θ2 |
80 |
80 |
231847 |
235892 |
212734 |
226824
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| 8. 8θ3 |
80 |
80 |
220105 |
153560 |
158086 |
177250
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Fitting a Straight Line

Image 5 shows the best fit line of the data from the calibration table.
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