title: Electron microscopy of native DNA in sea urchin cells.
mesh_terms: D002918:Chymotrypsin / Q000494:pharmacology; D004247:DNA / Q000032:analysis*; D003851:Deoxyribonucleases / Q000494:pharmacology; D004447:Echinodermata / Q000032:analysis*; D004492:Edetic Acid / Q000494:pharmacology; D004625:Embryo, Nonmammalian / Q000032:analysis; D008297:Male; D008854:Microscopy, Electron; D013094:Spermatozoa / Q000032:analysis; D014357:Trypsin / Q000494:pharmacology
chemical_list: D004247:DNA; D004492:Edetic Acid; D003851:Deoxyribonucleases; D002918:Chymotrypsin; D014357:Trypsin