Loading Buffer/Sample Buffer; Molecular Weight Marker; Troubleshooting - VWR PerfectBlue Maxi S Instruction Manual

Instruction Manual PerfectBlue

Loading buffer/Sample buffer

Samples are prepared and mixed with loading buffer before applying to the prepared gel. Sample
buffers contain dyes for visibility and glycerol to provide weight to the samples. This increased sample
density ensures samples load evenly into the wells and do not float out during loading. Dyes also mi-
grate toward the anode end of the electrophoresis chamber at predictable rates allowing the gel run to
be monitored. In 0.5 x TBE gels, bromophenol blue migrates at the same rate as 300 bp DNA frag-
ments and xylene cyanol approximately at the same rate as 4 kbp DNA fragments.
6 x DNA sample buffer:

Molecular weight marker

Markers are run on each gel to monitor the quality of sample separation and to enable a size estimation
of specific bands. By running a known marker of a specific concentration in parallel, the DNA amount
of the unknown samples can be estimated. VWR offers an extensive range of DNA and RNA markers.
For detailed information please contact us or visit www.de.vwr.com.

TROUBLESHOOTING

Some possible solutions to potential problems are listed below. If these suggestions are unclear or un-
successful, please contact the VWR service team (see 'TECHNICAL SUPPORT AND ORDERING
INFORMATION').
Problem: Agarose leaks into casting chamber when pouring gel
Check to see if the gasket is firmly seated in the End Gates and in the grooves on the ends of the gel
tray. Reseat gasket if necessary by removing and rinsing under warm running water, then reseat evenly
in the tray groove. Take care of an equal reseating of the gaskets in to the grooves of the End Gates.
Problem: Bands seem to be running at an angle (Gel smiling).
Check to be sure the casting is being done on a level surface. Also confirm that the gel tray is inserted
all the way into the unit and rests on the platform for level gel casting. The voltage may be too high. Try
lowering the voltage setting on the power supply. Electrophoresis buffer may have been prepared with
wrong or expired chemicals. Perhaps no electrophoresis buffer has been used for preparing the gel
solution. Check if the stock solution of the electrophoresis buffer was diluted correctly for the preparation
of the working solution.
Problem: Samples seem to be running unevenly in certain areas.
Check that the platinum electrode wire is intact and running evenly across the base of the chamber and
up the side to the junction of the banana plug. The unit should produce small bubbles as the current
passes through. If there appears to be a break in the electrode connection, contact VWR immediately.
This problem may also be caused by regularly casting with very hot agarose gel (> 60 °C). Always cool
the melted agarose to below 60 °C before casting to avoid warping the gel tray. Warping the gel tray
will cause all subsequent gels to be cast unevenly and hence cause bad electrophoretic separation.
VWR_v0617_E
Horizontal Maxi Gel Systems
™
0.25 % (w/v) bromophenol blue
0.25 % (w/v) xylene cyanol FF
30 % (v/v) glycerol
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