The cell cycle can be arrested and the unreplicated chromosomal regions can be repaired if the cell cycle checkpoint ATR is activated and DNA replication is stopped. Clofentezine microgravity in space is a kind of culture stress which can induce the inhibition of cell proliferation, the occurrence of cytoskeleton disorder, the Cinoxacin structural change in a bipolar spindle, the arrestment of a cell cycle and/or the alteration of a gene expression. However, little work is done on the chromosome instability of human peripheral blood lymphocytesunder space microgravity or simulated microgravity. Therefore, our study on the effect of simulated microgravity is continued by keeping human PBL cells under simulated microgravity in a Rotary Cell Culture Systembioreactor to investigate the effect of simulated microgravity on the structural chromosome instability of PBL cells. This article is a summary report on our recent work to complete our study on the effect of simulated microgravity, and it reports new findings that extend the results we reported earlier. A special culture medium or medicine was used to make the observation of chromosome breakages easy for the present study. The medium usually used for medical study is a folate-free M199 medium with low serumor RPMI-1640 with 20% FBS and aphidicolin, a medium with DNA replication inhibitor. The fragile site can be considered to be successfully induced when FRA3B is observed. And the presence of an expression of fragile site means the repair of DNA is below the actual damage degree of DNA. So, the inhibition of DNA replication can be identified through the observation of the change 
in chromosome morphological structure. This is the theoretical basis for our study on the effect of simulated microgravity on the replication of DNA and the structural chromosome instability of human PBL cells. As shown in Fig.1c-d, Fig.4 and Table S1, the expression rate of chromosome fragile site had no significant difference among the three individuals, but it had a significant increase after the cells were kept under simulated microgravity for 72 hours. This meant simulated microgravity enhance the inhibition of DNA replication and induces the change in chromosome structure. It can be seen from the morphologic changes that more gaps occur in larger chromosomes. It can therefore be concluded that simulated microgravity has no effect on the numerical chromosome instability of human PBL cells,but it enhances the structural chromosome instability of human PBL cells through the inhibition of DNA replication and the reduction of DNA repair. So, the mechanism of chromosome fragile site induced by simulated microgravity can be explained using the changes which occur in the chromosome structure of human PBL cells, the DNA replication and repair under simulated microgravity. The use of six primers produces more amplicons during amplification reaction. However, this high reproduction of the target amplicon in turn bears an elevated risk of cross contamination of subsequent samples by aerosolized products. The LAMP reaction was also carried out with DNA extracted from heat-treated ostrich meat. A strong signal appeared even after heat treatment of the meat prior to DNA extraction at 100uC up to 120 min. In addition, DNA was also extracted successfully from fried meat with oil and spices. This demonstrates the robustness of LAMP in the presence of PCR inhibitor substances like salt, spices and cooking oil.