Over the course of the last week, we have been trying to use the IRIS and MODI-TOF to make measurements of the PSA antigen. PSA is used to signal the possibility of prostrate cancer. Unfortunately, it has only about a 50% chance of being correct in making the proper diagnosis. We hope to make a better prediction of the diagnosis with more accurat measurements.
We have had difficulty in making accurate measurements for two reasons. First, the polymer base to which the antibody attaches is not consistent in maintaining its leel of material. Second, as we clean off the antibody and antigen levels, we found that the levels of antibody and antigenchange.
We spent much time trying different chip configurations in order to maintain the polymer, antibody and antigen quantities. Unfortunately, we couldn't make accurate measurements with the IRIS that woul let us dtermine the amounts of antibody and antigen involved in each bonding event.
However, we were able to use the MALDI-TOF to show accurately that there were PSA antigen components which were singly, doubly, and triply charged during the MALDI laser interaction with the PSA.
We have developed a new chip design and cleaning process to use in the preparation of our new chip. We plan to test this new design and process within the next week.