Labeling ADC’s with Fab-pHast to study lysosomal trafficking

• This episode highlights our pHast line of conjugates. pHast conjugates are one of our fastest tools to quantitatively test your primary antibody’s specificity, binding, and internalization, providing results in 1 day. 
• The pHast conjugate binds to your primary antibody via a secondary antibody cross-linked to a pH-dependent fluorescent reporter. This fluorescent reporter will increase intensity as the pH of its surroundings becomes more acidic, such as you would see on the inside of a cell. 
• This is a publication using our Fab-pHast Human. 
  • Kinneer K, Meekin J, Tiberghien AC, Tai YT, Phipps S, Kiefer CM, Rebelatto MC, Dimasi N, Moriarty A, Papadopoulos KP, Sridhar S, Gregson SJ, Wick MJ, Masterson L, Anderson KC, Herbst R, Howard PW, Tice DA (2018) SLC46A3 as a potential predictive biomarker for antibody-drug conjugates bearing noncleavable linked maytansinoid and pyrrolobenzodiazepine warheads. Clin Cancer Res 24(24):6570-6582. doi: 10.1158/1078-0432.CCR-18-1300 PMID: 30131388
• Their objective was to develop biomarkers to uncover the underlying mechanism of resistance by certain cell lines for antibody drug conjugates (ADCs). 
• The authors labeled ADCs with Fab-pHast human to study lysosomal trafficking. Desired time points and fluorescence were quantified by flow cytometry. 
• The loss of SLC46A3 expression was found to be a mechanism of innate and acquired resistance to ADCs carrying the warheads DM1 and SG3376.  

episode20, episode43