Analysis of DNA content in multidrug‐resistant cells by image and flow cytometry

Abstract

Nuclear DNA content was assessed in multidrug-resistant (MDR) cells by image and flow cytometry. Two human MDR cell lines (K562-Dox and CEM-VLB) obtained by in vitro drug selection and overexpressing mdr1 gene were compared to their respective sensitive counterparts (K562 and CCRF-CEM) and to the MDR hamster LR73-R cell line obtained by transfection of mouse mdr1 cDNA. Both cell lines obtained by selection displayed a decreased DNA content, as measured by image cytometry after Feulgen staining, or by flow cytometry after staining with propidium iodide, ethidium bromide, or Hoechst 33342. This decrease was not accompanied by changes in cell cycle phase distribution of cells. Moreover, image cytometry of cells stained after various hydrolysis times in 5 M HCl indicated that MDR cells displayed the same hydrolysis kinetics and sensitivity as drug-sensitive cells with a well-preserved stoichiometry of the Feulgen reaction. LR73-R cells transfected with mdr1 cDNA exhibited only a very limited change in propidium iodide staining as compared with sensitive LR73 cells, suggesting that mdr1 gene overexpression alone could not account for the alterations in DNA content observed in the selected MDR cells.

Intracellular protein and nucleic acid measured in eight cell types using deep‐ultraviolet mass mapping

“…Our measurement for a White Bovan male falls at the low end of the range of the literature values for various other breeds of male and female chickens (2.33-2.54 pg, Ref. [18][19][20][21][22][23][24][25].…”

“…We next addressed calibration to a known nucleic acid standard using chicken RBC nuclei, a common calibration standard for genomic content in flow cytometry (17)(18)(19)(20). As an approximation, we assumed the same effective epsilons for protein as for hRBCs.…”

Nuclear chromatin patterns in 3 glucocorticoid-resistant RPMI 8226 human myeloma cell sub-lines: Correlations with cell growth and immunological phenotype

“…After acid hydrolysis with 5N HCl for 30 minutes, they were stained by the Feulgen method as previously described. 18 Image cytometry was performed with an image analysis system (Samba Technologies, Meylan, France) coupled to a color 3CCD Camera (XC-007P, Sony Corporation, Japan) and a microscope (Axioskop, Karl Zeiss, Oberkochen, Germany). Measurements were made with a planachromat x40 objective.…”

Evaluation of the potential cytotoxicity of metals associated with implanted biomaterials (II)

“…Redox reactions initiated by the materials or leachable compounds from the materials may oxidise to GSSG, which is then secreted from cells. GSH content will decrease with increase of cytotoxicity [6,7]. Therefore, cell cytotoxicity can be quantitatively approached by determining the level of GSH.…”