Thermo Scientific NanoDrop One, User Manual

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14
Measure OD600
136 NanoDrop One User Guide Thermo Scientific
Related Topics
• Instrument Settings
Additional monitored
wavelength (

)
Any wavelength between
250 nm and 700 nm User-defined wavelength. Enter an additional wavelength to
measure if desired (useful for dilute samples that exhibit low
absorbance at 600 nm).
If an alternative wavelength is specified, use this equation to
calculate cell concentration:
c = A
(

)
* factor
(

)
where:
c = analyte concentration in cells/mL
A (

) = UV-visible absorbance at specified wavelength in
absorbance units (A)
factor(

) = 1/(

(

) * b) in mL/cell-cm
where:

(

) = molar absorption coefficient (or extinction
coefficient) at specified wavelength
b = pathlength in cm (1.0 cm for the NanoDrop One
instruments)
Cell number
conversion factor (10
8
)
Any number User-defined factor. Generally accepted factor for measured cell
type, or one derived empirically using a solution of study cells at
known concentration using the same media.
Default value is 1x10
8
which is the generally accepted factor for
most bacterial cell suspensions such as E. coli.
Tip : The factor is wavelength specific for each cell type and can
be affected by the type of media used for the measurements.
Ideally, the factor should be determined empirically using a
solution of the study cells at a known concentration using the
same media.
Setting Available Options Description