The identifications were from the same sample where the presence of the ion trap MS2 spectra, in addition to each event in HCD MS, improved peptide identification rates drastically. We can, therefore, speculate that SCREEN will have the ability to quantify 5,000 proteins or greater with CID on new generation of tribrid type of orbitraps called Eclipse . We expect similar results from TIMS TOF PRO (Bruker, Billerica, MA) and Zeno TOF (SCIEX, Canada) due to the speed of MS2 data collection and better separation of ions clouds before entering the TOF instrument. Another important factor for the new platform's identification rate is the amount of data quantified for the same protein across all cells in the study. In the original SCoPE method only the most abundant 150-200 protens were identified in all cells across the study. Subsequently this percent dropped very quickly with only about 5% of the cells identified with 1200 proteins. With the new platform approximately 500 proteins with quantitative data were analyzed for cell heteroginiety from all cells in the study. This improvement was possible with only two changes 1) more that 200 cells are now allowed in the carrier channels under the SCoPE X MS2 type of acquisition mode and 2) the istrument no longer operating in DDA (data dependent aqcuisintion) mode, but rather it operates under the strict LTA (library based targeted acquisition) approach to remove any stohasticity of ion detection-isolation for MS2 mode due to the undersampling effect.