Project:OD600 Measurement: Difference between revisions

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== OD600 device ==
== OD600 device ==


[[File:OD600-proto-1.png|thumb]]
The idea is to make a cheap, robust, reliable alternative to a dedicated and expensive device. The initial brain storming is to take a 600 nm source, (or a broad wavelength source of light which includes 600 nm and use a BP filter) and a level detector, and calibrate it to match 0.4 at OD600 on a proper spectrophotometer..


The idea is to make a cheap, robust, reliable alternative to a dedicated and expensive device. The initial brain storming is to take a 600 nm source, (or a broad wavelength source of light which includes 600 nm and use a BP filter) and a level detector, and calibrate it to match 0.4 at OD600 on a proper spectrophotometer..
[[File:OD600-proto-1.png|450px]]


The initial attempt was to use a white led with a filter for something approximating 600nm


[[File:14853907550 b7212c3efe k.jpg|350px]]


The initial attempt was to use a white led with a filter for something approximating 600nm
At the moment the main issue is that the LDR (light dependent resistor) only sees about 20 ohms of difference between the initial inoculation and the mid-log phase, which shows as 0.4 OD600 on a spectrophotometer.


[[File:14853907550 b7212c3efe k.jpg|thumb]]
It really needs some amplification and a lot more light shielding.


the second idea (once the 605nm LEDs had turned up from ebay);


[[File:OD600-proto-2.png|450px]]


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At the moment the main issue is that the LDR (light dependent resistor) only sees about 20 ohms of difference between the initial inoculation and the mid-log phase, which shows as 0.4 OD600 on a spectrophotometer.
It really needs some amplification and a lot more light shielding.


the second idea (once the 605nm LEDs had turned up from ebay);
[[File:OD600-proto-2.png|450px]]


If you don't have access to a spectrophotometer, (or even if you do), this should be a convenient way to estimate OD600 values for your sample
If you don't have access to a spectrophotometer, (or even if you do), this should be a convenient way to estimate OD600 values for your sample