A Simple Plate Based Assay Using pH Sensor Dye to Screen for Internalizing Antibody
Poster Oct 09, 2015
Nidhi Nath, Becky Godat, Cesear Corona, Chad Zimprich, Mark McDougall, Poncho Meisenheimer, Marjeta Urh
Receptor mediated internalization is a key mechanism of action (MOA) for antibody drug conjugates (ADCs). However, current methods of studying antibody internalization have several limitations including: 1) A multistep process not suitable for screening; 2) Low signal-to-background ratios; 3) Not suitable for kinetic measurements. We have developed a method that mitigates problems associated with traditional internalization assays. The method includes: 1) A water soluble, bright and photo-stable pH sensor dye (pHAb) to study internalization; 2) An optimized method for conjugating pHAb dyes to antibodies directly from the cell media; 3) A 96-well, plate-based assay with high signal-tobackground ratios for real time measurement of internalization and screening internalization.
We utilized paired synthetic crRNAs coupled with our synthetic tracrRNA in cells transduced with lentiviral Cas9 to perform a functional knockout on hsa-miR-221. This three-part system (crRNA, tracrRNA and Cas9) has demonstrated efficient gene editing when used with only one guide RNA, but the goal was to use two crRNAs to remove the entire stem-loop.READ MORE