Bio-Rad Helios® Gene Gun System - Manual (Page 49)

Fig. 26. Representative cross-section showing penetration of gold particles into water agar after
discharge with a helium pulse.
10.7 Quantitation of DNA in Cartridges
This procedure can be used for estimating the amount of DNA in cartridges when 0.5 µg
or more of DNA has been loaded per tube.
Materials
10 mM Tris, pH 8.0, 1 mM EDTA 1,000 µl micropipettor and tips
Ultrasonic cleaner UV spectrophotometer
Vortexer Quartz cuvettes
Microfuge
Procedure
1. Place five 0.5" cartridges in a microfuge tube and add 500 µl of TE.
2. Sonicate and/or vortex to dislodge gold and solubilize the DNA. Spin for 5 min in a
microfuge to pellet gold.
3. On a spectrophotometer determine the A
260
by reading against a TE blank. If 100% of the
DNA were precipitated onto the microcarriers, the A
260
readings should be as follows:
Plasmid/cartridge A
260
0.5 µg 0.1
1.0 0.2
2.0 0.4
4. DNA sample may also be analyzed by restriction enzyme digestion and analysis by agarose
gel electrophoresis.
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