ArticleOn Cell Membrane Lipid Fluidity and Plant Lectin Agglutinability. A Spin Label Study of Mouse Ascites Tumor CellsLesin, Eric S.The fluidity of the plasma membrane of Sarcoma 180 mouse ascites tumor cells has been studied in viable cells using fatty acid spin labels. The order parameter was found to vary from 0.61, approximately four carbon bond lengths removed from the membra . . .