Optical density measurements using PathCheck Technology

UV/VIS spectrophotometers and microplate readers differ fundamentally in their beam geometry. In spectrophotometers, samples are read through cuvettes or tubes with a horizontal, 1-cm light path, making assays based on extinction coefficients straightforward. In microplate readers, the vertical light beam results in a pathlength that depends on the volume of fluid in each well. This problem has been remedied with Molecular Devices PathCheck Technology, which automatically corrects optical density (OD) measurements to a 1-cm pathlength.

These application notes discuss the principles and uses of PathCheck Technology:

• Optical density measurements automatically corrected to a 1-cm pathlength with PathCheck Technology
• Phenolic compounds measurement in red wines using the SpectraMax Plus 384 Microplate Reader
• DNA and RNA absorbance measurements using SpectraMax Microplate Readers