INTERLAB STUDY

We participated in the Fourth International InterLab Measurement Study. They asked us to measure the fluorescence of GFP in different devices in an attempt to explore the question, “How close can the numbers be when fluorescence is measured all around the world? “.

We followed the same protocols as directed in the iGEM protocol page.

Materials

E.coli DH5-alpha: Competent cells were purchased from TOYOBO
Plate reader: SH-9000Lab

Result

1. Calculation

Table 1. Abs600 of LUDOX-S40 and H₂O
	LUDOX-HS40	H₂O
Replicate1	0.034	0.025
Replicate2	0.031	0.024
Replicate3	0.032	0.025
Replicate4	0.031	0.023
Arith.Mean	0.032	0.023
Corrected Abs600	0.00775
Reference OD600	0.0425
OD600/Abs600	5.483871

2. FIuorescein fluorescence standard curve

Table.2 shows the fluorescence measurement data, and Fig.1 shows the standard curve. We couldn’t measure the value of fluorescein fluorescence at 50, 25, 12.5, 6.25, 3.125 μM because they exceeded the measurable range.

Table 2. fluorescence data for fluorescein standard curve
uM Fluorescein	1.5625	0.78125	0.390625	0.195313	0.097656	0.048828	0
Replicate 1	57809	29980	15540	7861	3913	1949	3
Replicate 2	58424	30336	15369	7579	3948	1993	3
Replicate 3	58075	29993	15535	7723	3908	1999	2
Replicate 4	57953	29694	15532	7798	3935	2044	4
Arith. Mean	58065.25	30000.75	15494	7740.25	3926	1996.25	3
S.D.	262.7171	262.665	83.39864	121.4012	18.77942	38.86194	0.816497

3. Cell measurement

Table 3.Abs600 (cell concentration)
	0h	2h	4h	6h
Negative Control (Colony 1)	0.00475	0.0275	0.14125	0.25875
Negative Control (Colony 2)	0.00975	0.0315	0.13275	0.235
Positive Control (Colony 1)	0.007	0.01475	0.12125	0.25875
Positive Control (Colony 2)	0.00825	0.019	0.1235	0.26925
Device 1 (Colony 1)	0.0045	0.00375	0.00875	0.01
Device 1 (Colony 2)	0.0045	0.00325	0.009	0.007
Device 2 (Colony 1)	0.006	0.01825	0.12825	0.2665
Device 2 (Colony 2)	0.00925	0.02325	0.141	0.26375
Device 3 (Colony 1)	0.0065	0.02225	0.13425	0.2735
Device 3 (Colony 2)	0.0105	0.0275	0.144	0.26325
Device 4 (Colony 1)	0.00375	0.00325	0.00875	0.0445
Device 4 (Colony 2)	0.0065	0.004	0.0085	0.0125
Device 5 (Colony 1)	0.00575	0.02375	0.14775	0.28175
Device 5 (Colony 2)	0.00875	0.019	0.1275	0.27675
Device 6 (Colony 1)	0.006	0.02425	0.1505	0.2855
Device 6 (Colony 2)	0.0085	0.02125	0.1005	0.2625

Table 4: fluorescence
	0h	2h	4h	6h
Negative Control (Colony 1)	39.5	26.25	123	79
Negative Control (Colony 2)	34.5	15	120	112
Positive Control (Colony 1)	72.5	316.25	1272.75	2534.25
Positive Control (Colony 2)	68.25	318.25	1269.25	2440.25
Device 1 (Colony 1)	557.5	563	940.5	1046.5
Device 1 (Colony 2)	461.75	355.25	633.75	781.25
Device 2 (Colony 1)	83.75	374.75	2280.25	5128.5
Device 2 (Colony 2)	116.25	494.25	2128.75	5528.5
Device 3 (Colony 1)	3	29.5	154.75	232.75
Device 3 (Colony 2)	28.5	29.75	161	258.5
Device 4 (Colony 1)	94	172.5	327.75	769
Device 4 (Colony 2)	71.75	165.5	286	443.5
Device 5 (Colony 1)	7.5	196	614.5	858.25
Device 5 (Colony 2)	14.5	189.75	796.75	987
Device 6 (Colony 1)	60.25	29.5	129.5	164
Device 6 (Colony 2)	33.75	26.5	97.75	165

Table 6. Value of Flu/Abs₆₀₀
	0h	2h	4h	6h
Negative Control (Colony 1)	0.045689	0.00469	0.004282	0.001499
Negative Control (Colony 2)	0.018247	0.002376	0.004481	0.002352
Positive Control (Colony 1)	0.055533	0.105486	0.051542	0.048113
Positive Control (Colony 2)	0.04131	0.082437	0.050482	0.044579
Device 1 (Colony 1)	0.607923	0.745125	0.532061	0.520307
Device 1 (Colony 2)	0.522086	0.640948	0.355477	0.553925
Device 2 (Colony 1)	0.070761	0.101285	0.087415	0.094541
Device 2 (Colony 2)	0.063885	0.104249	0.074675	0.103012
Device 3 (Colony 1)	0.001716	0.006526	0.005688	0.004194
Device 3 (Colony 2)	0.01537	0.005312	0.005489	0.004827
Device 4 (Colony 1)	0.118182	0.265189	0.184017	0.084842
Device 4 (Colony 2)	0.054166	0.218167	0.166671	0.177319
Device 5 (Colony 1)	0.00281	0.040555	0.020409	0.014984
Device 5 (Colony 2)	0.007484	0.049747	0.030945	0.017517
Device 6 (Colony 1)	0.050096	0.005969	0.004225	0.002821
Device 6 (Colony 2)	0.024278	0.006149	0.004835	0.003078