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Fig. 2 | BMC Biology

Fig. 2

From: DPF is a cell-density sensing factor, with cell-autonomous and non-autonomous functions during Dictyostelium growth and development

Fig. 2

Purification of the density aggregation activity. a The cell-free, > 30-kDa conditioned media from WT cells were fractionated on mono Q, phenyl sepharose (PS), wheat germ agglutinin (WG), and Superose 12 columns. Fractions were assayed for density-dependent aggregation activity on WT cells at low cell density (< 20 × 103 cells/cm2). Selected bound or flow through (FT) fractions separated by SDS gel electrophoresis are shown. Gels were stained with silver and protein bands indicated from Superose 12 fractions (e.g., 11 and 12) were used for peptide sequencing. Proteins matching each band are indicated (see Additional file 3: Figure S3). b The procedure followed Fig. 2a, but using conditioned DB from PDE1-null cells. Superose 12 fractions 22, 23, and 24 were used for MS/MS peptide sequencing. c Comparison of Superose 12 fractionations of conditioned DB from WT or PDE1-nulls cells, with protein profiles, relative MW positions, and activity position shift indicated. Relative fractionation differences for the proteins in Fig. 2a are also shown

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