Hi,

We are not measuring optical density of bacteria at 600 nm in general. The OD depends on color of media culture when it is Yellow used us 600 nm.

please look pig. in attach file

I can think of two reasons: a) the majority of previously described protocols use 600 nm; b) OD increases with decreasing wavelength, and the relationship between true cell density and OD departs significantly from linearity if OD > 0.5. Hence choosing 600 nm affords measurements that are both sensitive enough and not too much off linearity for most purposes.

Wavelength of 590nm has been utilized also

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Hi,

We are not measuring optical density of bacteria at 600 nm in general. The OD depends on color of media culture when it is Yellow used us 600 nm.

please look pig. in attach file

Noted, and thank you for taking your time in answering my concern!

600 nm

Hi there, you can use different wavelengths. The absorption spectrum tends to be a straight line with inclination downwards in direction of higher wavelengths. OD600 is the standard. If you don't have a particular reason to divert from 600nm, it is recommended you don't do it, because you would have to explain why you did it.

600 nm