Confocal immunofluorescent image of two Gefinitib (Iressa) treated non-small cell lung cancer cell lines. HCC827 cells have the E746_A750 deletion in exon 19 of the EGFR gene, and are highly sensitive to Gefitinib. H1975 cells have the (T790M) mutation that confers Gefitinib-resistance. Both cell lines were treated and then double-labeled with Phospho-S6 Ribosomal Protein Rabbit mAb (Alexa Fluor® 488 Conjugate) #4854 and Phospho-Tyrosine Mouse mAb (Alexa Fluor® 647 Conjugate) #9415. Untreated HCC827 (A) and H1975 (C) cells show bright phospho-S6 (green) and phospho-tyrosine (red pseudocolor) label. Phospho-S6 and phospho-tyrosine signals dramatically decrease following Gefitinib treatment in HCC827 cells (B), with little or no change in the Gefitinib-resistant H1975 cells (D).
Flow cytometric analysis of K562 cells, untreated (green) or Gleevec®- treated (blue), using Phospho-Tyrosine Mouse mAb (P-Tyr-100) (Alexa Fluor® 647 Conjugate) compared with a nonspecific negative control antibody (red).