Variation of percentage of hatched embryos labeled with different doses of antisense reagents. Rhodamine-dextran (RhDextran) or its conjugates of antisense 2'-O-methyl oligoribonucleotides against let-7, lin-4, lsy-6, mir-237 were injected into gonads of N2 worms at three different concentrations. Each time we collected 50 or more labelled embryos and counted hatched larvae the next day. Error bars are standard errors of two independent injections. Examination of embryos that failed to hatch revealed that most of them were arrested around 50-cell stage. Embryos, once hatched, developed into adults that appeared to be grossly normal.