SERVICES>Examples of tests>DNA Quantitation
Purified DNA is usually quantitated by either of two methods.
One is by the absorbance reading in a spectrophotometer at 260 nanometers.
The other is by using a double strand specific fluorescent dye called SYBR Green. This dye is highly sensitive and is used with standard known concentrations of lambda bacteriophage DNA. The fluorescence is read in the RotorGene real-time PCR instrument, and the concentrations are calculated by the instrument software.
The results to the right show standard DNAs (blue squares) and several samples of corn DNA (red diamonds) from grocery store corn. These corn DNAs were isolated from the kernel, the tassel, the husk, and the cob. Per weight of corn, the cob produced the least amount of DNA.