HIGH PERFORMANCE ICP-OES: A POTENTIAL PRIMARY MEASUREMENT TOOL FOR QUANTITATION OF TOTAL PLANT DNA
Savelas A. Rabb (839), Michael R. Winchester (839), Marcia N. Holden (837) and Yadu B. Tewari (837)
Quantitation of total plant DNA is important in the determination of genetically modified organisms (GMO) present in crops and prepared foodstuffs for US trade regulations. Currently, UV and fluorescence spectroscopy are used to determine plant DNA concentrations. However, possible DNA degradation as a result of extraction and purification methods or impurities in the DNA preparation can alter the accuracy of these measurements. At NIST, we are developing the high performance inductively coupled plasma optical emission spectroscopy (HP-ICP-OES) approach as a potential primary metrological tool for the quantitation of total plant DNA. Traditional ICP-OES measurements typically have concentration uncertainties of 5% to 10% or worse even though short term precision is often 1% or better. The utilization of simultaneous time-correlated internal standardization, long measurement times (several repeated measurements) and drift correction provide HP-ICP-OES measurements with concentration uncertainties on the order of 0.1%. The drift correction is especially unique as all standards and samples measured throughout the experiment are included to remove the effects of instrumental drift. Given the inherently atomic nature of the HP-ICP-OES technique, coupled with the fact that DNA contains one P atom per nucleotide base, this method will be founded upon the accurate measurement of total P in the DNA samples. As a result, HP-ICP-OES can potentially serve as a primary method for the quantitation of total plant DNA.
Author information: Savelas A. Rabb, Michael R. Winchester (mentor)
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