Lidstrom:NanoDrop
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Intro
- manual for our model, ND-1000
- "Proteins in solution absorb ultraviolet light with absorbance maxima at 280 and 200 nm. Amino acids with aromatic rings are the primary reason for the absorbance peak at 280 nm. Peptide bonds are primarily responsible for the peak at 200 nm." (referecne)
How NanoDrop correlates to Cuvette measurements for OD measurement of cell cultures
Plot one OD against the other:
Detection specifications
nucleic acids
- Low-end detection Limit: 2 ng/uL
- High-end:
- 3700 ng/ul (dsDNA)
- 3000 (RNA)
- 2400 (ssDNA)
protein
for BSA: NanoDrop 1000 0.1 mg/ml to 100 mg/ml
NanoDrop for Cell Culture
- Manual: "Note: The most distinct difference between the NanoDrop 1000 Spectrophotometer “absorbance” values for microbial cell cultures and those observed using classical cuvette based systems will be attributable to the shorter pathlength (1 mm vs. 1 cm.) Values may not be exactly 10 fold different as readings are dependent on both the optics of a specific spectrophotometer as well as the cell type in suspension."
- Sample Size Requirements:
- "Field experience has indicated that 1ul samples are sufficient to ensure accurate and reproducible results when measuring aqueous samples. However, if you are unsure about your sample composition or your pipettor accuracy, a 2 ul sample is recommended to ensure that the liquid sample column is formed and the light path is completely covered by sample."
- Cell Suspension Concentrations
- "Due to its shorter path length, the NanoDrop 1000 Spectrophotometer can measure absorbencies that are 10-fold higher than those measurable on a standard cuvette spectrophotometer. This makes it possible to directly monitor concentrated cell suspensions. Since the entire spectrum is displayed, diluted samples exhibiting very low ‘Absorbance’ at 600 nm can be monitored at lower wavelengths, for example 280 nm."
NanoDrop for Proteins
Resources
- Resource: [Protein instructions http://www.nanodrop.com/ND3/files/nanodrop_a280_olv_rev_3_11_r.pdf]
Comments
- Both protein and imidazole absorb in the 200-230nm range.
