1.   And, just as routinely, many have leftover embryos, which are frozen and stored.

2.   Later, the woman would throw the leftover embryos in the trash.

3.   Leftover embryos are usually frozen.

4.   Most scientist seek to use the cells from these leftover embryos for research, rather than create embryos for research purposes.

5.   One of the best sources of human stem cells is the many leftover frozen embryos from fertility clinics.

6.   The embryonic stem cells studied so far have been derived from the leftover embryos generated in fertility clinics.

7.   The leftover embryos are frozen and stored.

8.   Zames Thomson at the University of Wisconsin announced he had found the long-theorized cells in leftover embryos from a fertility clinic.

9.   At UCSF, Pedersen was working with leftover frozen embryos that were obtained from fertility clinics and would have otherwise been destroyed.

10.   Couples with leftover embryos can still donate them for research, but only if it is privately funded.