To support my in vitro experimental data, I start to try retina explant culture to check the axonal outgrowth of retina ganglia cell. I have tried many times with WT E18 mouse. The isolation of retina is good, and were cut into pieces round 200~500um. retina was put on the glass surface coated with laminin- (40 µg/ml) and poly-D-lysine- (100 µg/ml). The maintenance medium is containing Neural Basal medium and 1% N2 neuronal supplement (Gibco BRL), 1% penicillin-streptomycin (Gibco BRL), and 5 µg/ml insulin, 100 µg/ml transferrin, 20 nM progesterone, 0.1 mM putrescine, 30 nM selenium, 100 U/ml penicillin, 100 µg/ml streptomycin, and 0.4 mM glutamine. The problem is that the outgrowth rate of axon is very very low ( round 200~300 um round DIV10) compared to the previous report. some report said after 24h there is quite obvious axon out. some literatures used the collagen as matrix. some literatures just used glass coverslip as growth surface. I tried DRG explant culture with the same coating condition and medium condition, and the result was pretty good.