Bio-Rad Sub-Cell® Model 192 Cell - Manual (Page 16)

8. Power requirements vary depending on gel thickness, length and concentration, and type
of electrophoresis buffer used. Refer to Table 2.3 for relative sample migration rate for the
Sub-Cell Model 96 and Model 192 systems. Also, review Table 2.4 for DNA size migration
with sample loading dyes.
Note: Buffer recirculation is not required for most standard DNA and RNA agarose gel
electrophoresis. For most electrophoresis, TBE buffer is recommended. If buffer
recirculation is required, use the recirculating ports (Section 2.4).
Table 2.3 Relative Sample Migration Rates*
Bromophenol Blue
Cell Type Voltage migration rate
Sub-Cell Model 96 200 V 5.15 cm/hr
Sub Cell Model 192 200 V 6.20 cm/hr
* Note: These sample migration rates were determined based on a 0.5 cm thick 1.0% agarose gel using Bio-Rad Molecular Biology
Certified Agarose in 1x TBE buffer diluted from Bio-Rad Premixed 10x TBE Buffer). Migration rates will vary depending on the
voltage, current, and type of agarose or buffer used.
Table 2.4 DNA Size Migration with Sample Loading Dyes
Agarose
Concentration (%)
Xylene Cyanol Bromophenol Blue
0.5 – 1.5 4-5 Kbp 400-500 bp
2.0 – 3.0 * 750 bp 100 bp
4.0 – 5.0* 125 bp 25 bp
* Sieving agarose such as Bio-Rad AmpliSize agarose.
9. With the desired power requirements, begin electrophoresis. If using buffer recirculation,
electrophorese for 15 minutes before turning the pump ON.
Note: Buffer recirculation is optional for gels that require short run times. Gels run at
higher voltages (200 volts) may require recirculation to prevent heat or pH effects.
Recirculate the buffer at a rate of 300-500 ml/min. Do not pump at a higher rate, it will
cause the gel to float or slide off the tray causing variable sample migration rates during
electrophoresis.
10. After electrophoresis is complete, turn off the power. If using buffer recirculation, do not
turn the pump OFF and do not disconnect the tubing from the safety lid. Lift the safety lid
with the pump still ON and empty the buffer contained in the tubing and pump into the
base buffer chamber. When the tubing is empty, turn the pump OFF and disconnect the
tubing if desired.
2.6 Nucleic Acid Staining and Visualization
Gels can be removed from the base or gel tray for nucleic acid staining. The gel can also
remain on the UVTP gel tray for staining.
Ethidium Bromide Staining Procedure
1. Place the gel into the appropriate volume of 0.5 µg/ml ethidium bromide (EtBr) and stain
for 15–30 minutes. Use enough staining solution to cover the entire gel.
Caution: Ethidium bromide is a suspected carcinogen and should be handled with extreme
care. Always wear gloves, eye glasses and a laboratory coat. Dispose of used EtBr solutions
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