1 EXHIBIT 11.1 CHEMTRAK INCORPORATED COMPUTATION OF INCOME (LOSS) PER SHARE Three months ended Nine months ended September 30, September 30, -------------------------- ---------------------------- 1997 1996 1997 1996 ---------- ----------- ----------- ----------- Weighted average common shares outstanding 13,081,000 10,192,000 12,673,000 9,808,000 ========== =========== =========== =========== Net Income (loss) $ 161,000 $(2,087,000) $(2,788,000) $(6,372,000) ========== =========== =========== =========== Net Income (loss) per share $ 0.01 $ (0.20) $ (0.22) $ (0.65) ========== =========== =========== ===========