Principles Of Operation - PerkinElmer LabChip GX User Manual

Principles of Operation

The LabChip GX assays are based on traditional gel
electrophoresis principles that have been transferred to a chip
format. The chip format dramatically reduces separation time and
provides automated sizing and quantitation information in a digital
format.
The chip contains an interconnected set of microchannels that join
the separation channel and buffer wells. One of the microchannels
is connected to a short capillary that extends from the bottom of the
chip at a 90-degree angle. The capillary sips sample from the wells
of a microplate during the assay.
Some of the channels in the chip are larger than others. The larger
channels contain buffer. During the chip preparation, the smaller
channels and some of the wells are filled with sieving gel and buffer.
After the channels are filled, the chip functions as an integrated
electrical circuit. The circuit is driven by the 7 electrodes in the
electrode cartridge that contact solutions in the chip's wells when
the chip holder is closed. Each electrode is connected to an
independent power supply that provides maximum control and
flexibility.
The polymer filling the smaller channels in the chip is designed to
sieve DNA/RNA fragments or proteins by size as they are driven
through it by means of electrophoresis, similar to using agarose or
polyacrylamide gels. The sample and sieving buffers also contain a
fluorescent dye that gets brighter upon binding to double-stranded
DNA, RNA, or protein/SDS complex. (Protein, Glycan, and Protein
Charge Variant assays are only supported on LabChip GX II
instruments.)
V4.2
Figure 1. DNA/RNA Chip and Protein Chip Schematics
LabChip GX User Manual
Introduction 19
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