AIM:Flow cytometry was used to evaluate the effects of short-term storage conditions(fresh,frozen at-80℃for 7 d,and stored at 4℃for 7 d)on the median fluorescence intensity(MFI)of antibodies and the percentage of immune cell subsets in mouse peripheral blood mononuclear cells(PBMCs)and splenocytes.METHODS:The PBMC and splenocyte suspensions from six male Kunming mice were collected and analyzed under three different processing con-ditions to compare differences in the antibody MFI and percentages of monocyte subsets(Ly-6clow/Ly-6cmedium/Ly-6chigh),macrophages(M1/M2),and dendritic cells.RESULTS:Both tissue and antibody specificity were demonstrated by changes in the antibody MFI values.Following storage at-80℃,the MFIs of certain antibodies(such as CD45 and F4/80 in PBMCs,and CD115,Ly-6c,F4/80,CD80 and MHC-II in the spleen)were similar to those of the fresh groups,where-as after storage at 4℃,the MFIs of other antibodies(such as 7-AAD,CD115,Ly-6c and MHC-II in PBMCs,and CD11b,CD206 and CD11c in the spleen)were closer to those of the fresh groups.The MFI of most of the examined anti-bodies varied significantly following storage.Both storage conditions significantly reduced the viability of PBMCs and sple-nocytes.In PBMCs stored at 4℃,the percentages of total monocytes,Ly-6cmedium/Ly-6chigh monocytes,total macrophages,and dendritic cells were similar to those in the fresh group.Compared with the fresh group,both storage groups presented significantly lower percentages of M1 macrophages and dendritic cells(P<0.05).There were no statistically significant differences in the percentages of total monocytes,Ly-6cmedium monocytes,Ly-6chigh monocytes,total macrophages,M1 and M2 macrophages,or dendritic cells in the spleen among the three groups(P>0.05).The percentage of Ly-6clow monocytes did not differ substantially(P>0.05)between the fresh and-80℃frozen groups but was significantly lower in the 4℃storage group than in the fresh group(P<0.05).CONCLUSION:The storage conditions of the samples had a substantial effect on the flow cytometry results(antibody MFI and cell subset percentages)of the PBMCs and splenic cells,with tissue specificity.If the percentage of immune cell subgroups(particularly monocytes/macrophages/dendritic cells)in PBMCs is highly important,storage at 4℃for 7 d is preferable.If the MFI values of specific antibodies(such as CD45 and F4/80)are important,freezing at-80℃may be more appropriate.If the MFI values of most antibodies or the percentages of criti-cal subgroups(such as total monocytes/Ly-6chigh/total macrophages/dendritic cells)in splenic cells need to be close to those of fresh samples,4 ℃ storage for 7 d is more effective.Freezing at-80℃is preferable if the MFI values of particular anti-bodies(such as CD115 and Ly-6c)need to be determined.

AIM:Flow cytometry was used to evaluate the effects of short-term storage conditions(fresh,frozen at-80℃for 7 d,and stored at 4℃for 7 d)on the median fluorescence intensity(MFI)of antibodies and the percentage of immune cell subsets in mouse peripheral blood mononuclear cells(PBMCs)and splenocytes.METHODS:The PBMC and splenocyte suspensions from six male Kunming mice were collected and analyzed under three different processing con-ditions to compare differences in the antibody MFI and percentages of monocyte subsets(Ly-6clow/Ly-6cmedium/Ly-6chigh),macrophages(M1/M2),and dendritic cells.RESULTS:Both tissue and antibody specificity were demonstrated by changes in the antibody MFI values.Following storage at-80℃,the MFIs of certain antibodies(such as CD45 and F4/80 in PBMCs,and CD115,Ly-6c,F4/80,CD80 and MHC-II in the spleen)were similar to those of the fresh groups,where-as after storage at 4℃,the MFIs of other antibodies(such as 7-AAD,CD115,Ly-6c and MHC-II in PBMCs,and CD11b,CD206 and CD11c in the spleen)were closer to those of the fresh groups.The MFI of most of the examined anti-bodies varied significantly following storage.Both storage conditions significantly reduced the viability of PBMCs and sple-nocytes.In PBMCs stored at 4℃,the percentages of total monocytes,Ly-6cmedium/Ly-6chigh monocytes,total macrophages,and dendritic cells were similar to those in the fresh group.Compared with the fresh group,both storage groups presented significantly lower percentages of M1 macrophages and dendritic cells(P<0.05).There were no statistically significant differences in the percentages of total monocytes,Ly-6cmedium monocytes,Ly-6chigh monocytes,total macrophages,M1 and M2 macrophages,or dendritic cells in the spleen among the three groups(P>0.05).The percentage of Ly-6clow monocytes did not differ substantially(P>0.05)between the fresh and-80℃frozen groups but was significantly lower in the 4℃storage group than in the fresh group(P<0.05).CONCLUSION:The storage conditions of the samples had a substantial effect on the flow cytometry results(antibody MFI and cell subset percentages)of the PBMCs and splenic cells,with tissue specificity.If the percentage of immune cell subgroups(particularly monocytes/macrophages/dendritic cells)in PBMCs is highly important,storage at 4℃for 7 d is preferable.If the MFI values of specific antibodies(such as CD45 and F4/80)are important,freezing at-80℃may be more appropriate.If the MFI values of most antibodies or the percentages of criti-cal subgroups(such as total monocytes/Ly-6chigh/total macrophages/dendritic cells)in splenic cells need to be close to those of fresh samples,4 ℃ storage for 7 d is more effective.Freezing at-80℃is preferable if the MFI values of particular anti-bodies(such as CD115 and Ly-6c)need to be determined.