The isolation and purification of at least two distinct macromolecular lipids from murine L1210 tumors either sensitive or resistant to the terephthalanilide NSC 38280 are described. The lipids are extracted from the tumors with chloroform:methanol and purified utilizing a series of gel permeation and affinity chromatography columns with chloroform:methanol elution. Preliminary characterization of the macromolecular lipids indicates that they have low molecular weights (>10,000 but <25,000) and are comprised of lipid, carbohydrate, and polyamino components. Significant differences were found between the component composition, molecular size, and column elution properties of the two lipids. One of the macromolecular lipids is extractable from both sensitive and resistant tumors and binds terephthalanilides, Cain quinoliniums, a carbanilide, bis(substituted aminoalkylamino)anthraquinones, and Adriamycin.