OBJECTIVE: To analyze 18F-fludeoxyglucose injection by Silica Gel TLC method.METHODS: TLC was adopted in which 18F-fludeoxyglucose injection(A) and mixture solution of 18F-FDG injection-acetonitrile(5∶95,V/V)(B) were used as testing solution.GF silica plate and G silica plate were used as stationary phase,and the mobile phase was acetonitrile: water(95∶5,V/V).RESULTS: The main peak Rf of testing solution A had a great fluctuation;The main peak Rf of testing solution B was 0.38～0.40.Radiochemical purity of 18F-fludeoxyglucose was more than 98%,and the Rf of radioimpurity 18F-and the by-product 18F-fludeoxymannose stood at 0.0 and 0.78 respectively.CONCLUSION: When testing solution B,the process of silica gel thin-layer chromatographic analysis is stable and reproducible,and the results meets the requirements specified in USP and are independent of the category of silica plate.

Alfalfa(Medicago sativa L.)is the most important legume forage crop worldwide with high nutritional value and yield.For a long time,the breeding of alfalfa was hampered by lacking reliable information on the autotetraploid genome and molecular markers linked to important agro-nomic traits.We herein reported the de novo assembly of the allele-aware chromosome-level genome of Zhongmu-4,a cultivar widely cultivated in China,and a comprehensive database of genomic variations based on resequencing of 220 germplasms.Approximate 2.74 Gb contigs(N50 of 2.06 Mb),accounting for 88.39％of the estimated genome,were assembled,and 2.56 Gb contigs were anchored to 32 pseudo-chromosomes.A total of 34,922 allelic genes were identified from the allele-aware genome.We observed the expansion of gene families,especially those related to the nitrogen metabolism,and the increase of repetitive elements including transposable elements,which probably resulted in the increase of Zhongmu-4 genome compared with Medicago truncatula.Population structure analysis revealed that the accessions from Asia and South America had rela-tively lower genetic diversity than those from Europe,suggesting that geography may influence alfalfa genetic divergence during local adaption.Genome-wide association studies identified 101 sin-gle nucleotide polymorphisms(SNPs)associated with 27 agronomic traits.Two candidate genes were predicted to be correlated with fall dormancy and salt response.We believe that the allele-aware chromosome-level genome sequence of Zhongmu-4 combined with the resequencing data of the diverse alfalfa germplasms will facilitate genetic research and genomics-assisted breeding in variety improvement of alfalfa.