Environmental Technology Verification Program: Environmental and Sustainable Technology Evaluations Report: ANDAlyze Lead-in-Paint Test Kit Qualitative Spot Test Kit for Lead in Paint

摘要

This report provides results for the verification testing of the Lead-in-Paint Test Kit for leadbased paint by ANDalyze. The following is a description of the Lead-in-Paint Test Kit, based on information provided by the vendor. The information provided below was not verified in this test. The ANDalyze Lead-in-Paint Test Kit utilizes a sensor/fluorimeter platform to quantitatively detect lead in paint. The test is based on a sensing technology which uses DNA to identify lead. Research done at the University of Illinois, Urbana Champaign used combinatorial biology to identify a particular DNA sequence that specifically binds to lead ion (Pb2+) and catalyzes the cleavage of another DNA sequence. These special DNA sequences capable of performing catalysis are called DNAzymes (DNA enzymes). ANDalyze has converted this patented technology into a test kit for lead. The DNA sequence specific for Pb2+ is linked to fluorophores/quencher pair as depicted in Figure 2-1. Two strands of DNA, an enzyme strand (shown in green) linked to a quencher and a substrate strand (shown in black) linked to a fluorophore are held together by DNA hybridization. The fluorescence of the fluorophore is quenched due to its close proximity to the quencher. In the presence of lead, the DNAzyme catalyzes the cleavage of the substrate strand which releases the cleaved fragment containing the fluorophore into solution thereby enhancing the fluorescence. The increased level of fluorescence upon reaction with lead can be measured using a fluorimeter. The rate of this increase is proportional to the lead concentration.