| | Re: Faint Bands
faint band means either:
1. There was insufficient quantity or concentration of DNA loaded on the gel. Increase the amount of DNA, but don't exceed 50 ng/band.
2. The DNA was degraded. Avoid nuclease contamination.
3. The DNA was electrophoresed off the gel. Electrophorese the gel for less time, use a lower voltage, or use a higher percent gel.
4. Improper uv light source was used for visualization of ethidium bromide-stained DNA. Use a shortwavelength (254 nm) W light for greater sensitivity. Note: For preparative gels, using a longer wavelength (312 nm) W light will minimize DNA degradation.