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After the separation, Quick, high-voltage runs, Slower, lower voltage runs – Hoefer HE33 User Manual

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Quick, high-voltage runs

Certain applications, such as screening samples or
checking sample purity, can be accomplished quickly
under high voltage conditions. Chill the base (-20 °C)
and limit the run to 5 minutes or less at 500 V.

Slower, lower voltage runs

A voltage gradient of 12 V/cm (150 V) separates 0.1
to 23 kb fragments of a Hind III digest of λ DNA
in 30 to 40 minutes (using 1% agarose gel and
0.5X TBE running buffer). Alternatively, using the
same solutions, this sample could be run at 24 V/
cm (300 V) with acceptable band resolution in 20 to
30 minutes. Chill the base before use.

Table 1: Voltage settings and recommended  
run settings

voltage 

gradient 

time  

(V) 

(V/cm) 

(min)

500

40

5*

400

31

10*

300

24

20*

200

16

30 to 40

150

12

30 to 60

* For rapid runs of 20 minutes or less, use 0.5X TBE and chill

the base to -20 °C before use.

Voltage and times are for 1% Agarose NA, 0.5X TBE and a

chilled base.

After the separation

Important! Turn off the power supply, disconnect the
leads, and remove the lid.

If no ethidium bromide was added to the gel or
sample before the run, stain the gel in a solution of
0.5 to 1.0 µg/ml ethidium bromide in water or buffer.

Clean the unit as described below.

Note: To calculate the voltage
gradient, divide the voltage
setting by the distance between
the electrodes (12.7 cm).