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The search for unknown mutations in genomic DNA is important in the study of
genes that play a role in the development of cancer and a variety of single
and multiple gene disorders. DNA polymorphisms are useful tools for ecological
and evolutionary studies of terrestrial, marine, and microbial organisms, with
applications ranging from species identification to delineation of population
structure to monitoring genetic diversity.
Two critical elements in screening DNA for sequence variations are providing
reliable temperature control and high-throughput efficiency. The DCode system
provides accurate temperature control from 5–70°C and can run 64 samples in
as little as 2 hours. It can be used to scan single-base changes with any
of the following electrophoresis techniques:
- Single-stranded conformation polymorphism (SSCP)
- Denaturing gradient gel electrophoresis (DGGE)
- Temporal temperature gradient electrophoresis (TTGE)
- Constant denaturing gel electrophoresis (CDGE)
For Ultimate Sensitivity, the DCode System Allows You to Combine Detection
Methods
For the highest throughput and efficiency, many laboratories use multiple techniques.
The ability to rapidly switch between methods or convert to a new technique
is critical in a fast-paced research environment. The DCode system meets the
demands of all major mutation detection techniques. Versatile features and distinct
benefits include:
- Temperature control options for electrophoresis runs between 5 and 70°C
- Modular design that allows laboratories to customize for current and future laboratory
demands
- Specialized accessory kits that simplify startup
- Research tools that can be added to the laboratory without investing in expensive
instrumentation
- Technique-specific reagents and controls that are optimized for DGGE, CDGE,
SSCP, and TTGE
- Application notes describing proven run conditions for all the major techniques
- The exclusive ability to perform powerful temporal temperature gradient
electrophoresis
The DCode system has a temperature control module with a microprocessor-controlled
heater, a buffer-recirculating pump, and a stirrer. For techniques requiring
temperature control, including SSCP, the gels are immersed in the buffer and
temperatures are regulated between 5 and 70°C. Any run temperature below
ambient can be achieved with the cooling tank, used in conjunction with an external
laboratory chiller.
The modular design allows the DCode system to expand as laboratory demands
require. For example, the DCode system can switch from running DGGE gels at
65°C to SSCP gels at 10°C by simply adding the SSCP adaptor kit
to the system. This flexibility lets you quickly add new research tools without
investing in new instrumentation. Systems configured for the primary application
can be expanded to perform any combination of methods, by supplementing the
core system with technique-specific adaptor kits.
WinMelt Software Takes the
Guesswork Out of Primer Placement
Mutations are most reliably
detected when the sequence difference
occurs in the lowest melting-temperature
domain of the DNA of interest.
In addition, optimal resolution
is attained only when the molecules
do not completely denature. The
addition of a GC clamp onto
one end of the DNA via PCR ensures
that the region screened is
in a lower melting-temperature
domain, and that the DNA will
remain partially double stranded.
This enhances both detection
and resolution. Windows-based
WinMelt software predicts
the melting profile of any DNA
sequence up to 3,200 bases. Placement
of primers and GC clamps can
be optimized by analysis of their
effect on the DNA melting profile.
Operation of WinMelt
software is simple. First, the
DNA sequence is imported from
a text file and the melting profile
is computed. The data appear
onscreen and can be graphed according
to user preference. The sequences
and melt data can be exported
for use in other programs. WinMelt
software is recommended for all
DGGE, CDGE, and TTGE applications.
Complete DCode Universal Mutation Detection Systems Offer Maximum Flexibility
The complete DCode system includes
all the tools required to cast
and run DGGE, CDGE, TTGE, and
SSCP gels. Control reagent kits
for each method and the WinMelt
software are also included.
DCode Adaptor Kits and Accessories
The DCode system offers individual
adaptor kits to allow convenient
custom configurations of systems
to meet the changing needs of
growing laboratories. A complete
line of accessory combs, spacers,
and glass plates is available.
In addition, WinMelt software
and the Model 475 gradient former
are offered separately.
DCode Electrophoresis and Control Reagents
Electrophoresis reagent kits customized for each application ensure that you
begin with the highest quality buffers and acrylamide available. Everything
required for electrophoresis is included. Our control reagents for DGGE, CDGE,
TTGE, and SSCP serve as learning tools to help set up new techniques as quickly as possible.
Comprehensive Protocols and References
Extensive bibliographies on each technique, and bulletins describing applications
using the DCode system, can assist in the optimization of protocols. Request
bulletin 2099 for our bibliography, or bulletin 2102 for DGGE, 2107 for CDGE,
2103 for TTGE, and 2104 for SSCP.
Note to D GENE Users
All of the DCode adaptor kits are compatible with the D GENE apparatus,
with the exception of the SSCP adaptor kit. To run gels below room temperature,
place the D GENE system in a coldroom or refrigerator equipped with electrical
outlets, and use the temperature controller to set the desired run temperature
(see bulletin 1935). The basic SSCP adaptor kit is compatible with the D GENE
system, but requires use of a coldroom for electrophoresis below room temperature.
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