Objective To obtain the specific primers for the detection of diatom 18srDNA polymorphism in Dianchi waters. Methods The primer 605F/605R and 467F/467R of diatom were designed in this study.The diatom specific primer A145 F/Dia516 R and common primer 18sF/18sR were selected from the published literature. Diatom DNAs were extracted from Dianchi water sample,then they were amplified,cloned,sequenced by four pairs of primers respectively,andthe results were compared to determine the their specificity and sensi...