A chalazion is caused by the oil in the gland becoming too thick to flow out of the gland or the opening of the gland being obstructed. Without anywhere to go, the oil builds up inside the gland and forms a lump in the eyelid.ach of the oil glands, called meibomian glands, produces oil that flows out of the gland into the tears. The oil exits from each gland through a tiny circular opening just behind the eyelashes of the upper and lower lids of both eyes.
Transcription activator-like effector nucleases (TALENs) are artificial restriction enzymes generated by fusing a TAL effector DNA-binding domain to a DNA cleavage domain.Restriction enzymes are enzymes that cut DNA strands at a specific sequence.rom Wikipedia, the free encyclopedia. Transcription activator-like effector nucleases (TALENs) are artificial restriction enzymes generated by fusing a TAL effector DNA-binding domain to a DNA cleavage domain. Restriction enzymes are enzymes that cut DNA strands at a specific sequence.
Biotechnology Index Glossary Nucleases: DNase and RNase Most of the time nucleases are the enemy of the molecular biologist who is trying to preserve the integrity of RNA or DNA samples. However, deoxyribonucleases (DNases) and ribonucleases (RNases) have certain indispensible roles in molecular biology laboratories.he most widely used nucleases are DNase I and RNase A, both of which are purified from bovine pancreas : Deoxyribonuclease I cleaves double-stranded or single stranded DNA. Cleavage preferentially occurs adjacent to pyrimidine (C or T) residues, and the enzyme is therefore an endonuclease.