Roche Nimblegen MS 200, Operator'S Manual

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2 | NimbleGen MS 200 Microarray Scanner Operator’s Manual v1.0
This unique dynamic autofocus procedure is more reliable than single
focusing routines, which concentrate on only one point of the slide.
Moreover, this dynamic autofocus procedure is less vulnerable to
disturbances such as dust on the slide surface.
Laser Excitation
The Microarray Scanner is designed for microarray imaging using
individual solid state lasers that emit light at wavelengths suitable for
exciting fluorescent dyes used as labels.
The lasers are able to excite Cy3- and Cy5-labeled samples to measure
fluorescence intensities in microarray analysis. Laser emission for excitation
of fluorescent dyes can be chosen at these wavelengths:
„
Green: 532nm
„
Red: 635nm
Other dyes similar to Cy3 and Cy5 can also be used, such as Alexa 555 and
Alexa 647 or DY 547 and DY 647.
Excitation intensity can be varied with neutral density filters located in a
filter wheel behind the lasers so that each laser can be adjusted separately
with its own filter device.
A reference photodiode is used for detecting the laser power.
Emission Filters
The Microarray Scanner is equipped with filters that are optimized for the
emission spectrum of the fluorescent cyanine dyes Cy3 and Cy5 and the
other dyes specified earlier.
Detection
Fluorescence emission is directed through filters before reaching the
photodetector. To detect photons emitted by the tagged molecules,
photomultiplier tubes (PMTs)
with very high sensitivity and low electronic
noise are used to convert the light energy into electric current that can be
measured. The resulting current is proportional to the incident emission
light at the photodetector.