Abstract: Objective To investigate if different RNA extraction methods could affect the total RNA concentration and integrity of samples dissected by LMD system from murine tooth germs.Methods According to the different RNA extraction methods,the samples were divided into three groups:RNA extraction kit group,classic Trizol method group and modified Trizol method group.The tooth germ tissues of the mandibular first molars of CD1 mice at E17 and PN2 stages were dissected by LMD6000 system.Total RNA was extracted from each group in the 3 ways.To ensure the integrity of RNA samples,quality check was adopted with Bioanalyzer 2100 System,Agilent.The 28 S /18 S ratios of ribosome RNA,RNA integrity numbers (RIN) and the peak patterns of the electrophoretograms were integrated as the indices of RNA integrity.The RNA concentration and integrity of all the groups were compared with SPSS statistical analysis software.Results The RNA concentration in modified Trizol method group was the highest,which had significant difference compared with the other two groups.The classic Trizol method group had higher concentration than RNA extraction kit group,however,the difference didn′t have statistical meaning.The comparison of RNA integrity among three groups showed no significant differences taking RIN numbers and 28 S/18 S ratios and electrophoretograms as indicators.Conclusions Our experiment preliminaryly proves that modified Trizol method can extract most total RNA compared with other two groups,while there is no stastically significant difference in RNA integrity among 3 methods.Modified Trizol method will be helpful to get chip experimental samples that meet the inspection standards for high flux experiment.