Section 5 Technical Tips - Thermo Scientific A2-OK Operating And Maintenance Manual

Section 5
Technical Tips
5-4 Horizontal System
Ethidium Bromide -
Ethidium bromide is ideal for the flurometric detection of nucleic acids in
gel electrophoresis. The addition of ethidium bromide to both the prepared
gel and running buffer is a convenient way to monitor separation and keep
a photographic log of gel runs. Ethidium Bromide is prepared as 10mg/ml
in distilled water and used as a stock working solution of 5.0ug/ml in the
electrophoresis buffer and gel. Mix ethidium bromide powder or tablet
thoroughly into solution checking for any precipitate and store at room
temperature protected from light.
Chart C
Amount of Agarose to prepare:
All approximate well volumes given in the chart below are based on a gel of
0.5cm thickness. Gel volume is determined by the following formula and
may be adjusted according to need or preference:
gel width(cm) x gel length (cm) x gel thickness (cm) = ml of agarose
Unit Agarose Volume in ml per gel thickness in cm.
Model # Gel size(cm) 0.25cm
A2-OK
Agarose Gel Loading Buffer
Samples are prepared and combine with gel loading buffer before applying
to the prepared gel. Sample buffer usually contains similar components to
the running buffer, dyes for visibility, and glycerol to provide some weight
to the samples. This increased sample density and color allows easy
visualization of the samples and ensures samples load evenly into the wells
and do not float out during loading. Dyes also migrate toward the anode
end of the electrophoresis chamber at predictable rates allowing the gel run
to be monitored.
The most commonly used loading buffer is glycerol, bromophenol blue,
and xylene cyanol.
0.5cm 0.75cm 1.0cm
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