Cleaning And Maintenance - 3B 1012852 Mode D'emploi

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Cleaning and Maintenance

Attention: Disconnect the electrophoresis chamber from power supply before cleaning.
The gel chamber and the combs should be cleaned with warm water immediately after each use. If necessary, a few drops of
a washing-up liquid can be added. Please do not use dishwashing brushes or the like, as this can damage the platinum elec-
trodes. Rinse the electrophoresis chamber after cleaning with distilled or demineralised water to prevent the formation of
limescale.
Never leave the chamber uncleaned for hours or even overnight as residues from gel or buffer can cause stains which are diffi-
cult to remove completely.
Attention: Please avoid the electrical connections being in contact with water. If however this does occur, please carefully
wipe dry with a soft cloth and allow to air-dry. Please do not use paper because it is often too rough and causes small scrat-
ches. Do not use a hair dryer either, as the hot air can damage connectors, fittings and the acrylic material.
Attention: Do not use ethanol nor other organic solvents for cleaning. It can cause cracks, scratches or other unwanted mate-
rial changes (blindness etc.).
Required Material and Processes
Electrophoresis buffer
The electrophoresis buffer provides the necessary ions for the electrophoresis process. It's addition provides a constant pH
value so that nucleic acids have the desired net charge. Nucleic acids are negatively charged in an alkaline up to neutral medi-
um. Normally, electrophoresis buffer contains components that protect nucleic acids from degradation, e.g. EDTA, which com-
plexes divalent cations and therefore inhibits DNases.
At this point, the frequently used TAE electrophoresis buffer for electrophoresis of DNA is described for non-denaturing con-
ditions. TAE stands for Tris-acetate-EDTA. You can either produce the buffer yourself or order it from 3B Scientific as a buffer
concentrate
Agarose, gel volumes and gel concentrations
Even though various agaroses are offered, the so called standard agarose is certainly of prime importance. For the casting of
an agarose gel in this chamber about 40 ml of gel solution is needed. Please prepare a little extra gel solution to allow for the
fact that small residues always remain in the vessel.
Optimal separation of molecules of different sizes will be achieved by varying the concentration of the gel according to the
information in the chart below.
Optimal separation ranges of the following DNA length (double-stranded DNA) corresponding to
various concentrations of agarose (standard agarose)
concentration of agarose (%) agarose (g) buffer (ml) optimal separation range (kbp)
0,5
0,7
1,0
1,2
1,5
2,0
Gel loading buffer
The samples which are to be analyzed need to be mixed with a suitable gel loading buffer before applying them to the gel. Gel
loading buffer contains dye(s) for tracking the run of the electrophoresis as well as glycerin, saccharose and the like. Therefore,
the prepared samples are heavier than the electrophoresis buffer and will decrease slightly into the gel slots during the sam-
ple application. Bromophenol blue and xylene cyanol are frequently used dyes for gel loading buffers. The patterns of their
run (or the so called co-migration to double-stranded DNA fragments) depend on the type of agarose, gel strength and the
type of electrophoresis buffer.
For a rough estimation: bromophenol blue migrates in 1xTAE electrophoresis buffer and 1%-standard agarose gel in the same
way as a DNA fragment of 650 base pairs. Under the same conditions, xylene cyanol migrates like a fragment with 5 000 base
pairs.
0,25 50
0,35 50
0,5 50
0,6 50
0,75 50
1,0 50
®
1 – 15
0,8 – 10
0,5 – 7
0,3 – 6
0,2 – 4
0,1 – 3