The use of biotin to demonstrate immunohistochemistry, Western blotting, and dot blots in university practical classes.

Immunological detection of proteins is an essential method to demonstrate to undergraduate biology students, however, is often difficult in resource and time poor student laboratory sessions. This method describes a failsafe method to rapidly and economically demonstrate this technique using biotinylated proteins or biotin itself as targets for detection. This negates the need for a specific primary antibody, saving cost and time. In addition, the easily available and safe reagents allow the methods to be readily adopted without specialist technical expertise. As a result, staff can confidently transfer ownership of the task to the student so as to also develop scientific inquiry skills which promotes student motivation and engagement.

The effect of Meibomian lipids and tear proteins on evaporation rate under controlled in vitro conditions.

The lipid layer of the tear film is associated with preventing evaporative loss. The ability of human Meibomian lipids to reduce evaporation in vitro was tested. Films of human or animal Meibomian lipids or mixtures of cholesterol and phosphatidylcholine were spread on the surface of either artificial buffer or on whole tears and placed on a mass balance that was enclosed in a sealed chamber. The temperature was adjusted to 37 degrees C and gas flow was controlled. Increasing the amounts of Meibomian lipids gave a very small reduction in evaporation. It was concluded from these in vitro experiments that prevention of evaporation from the tear film is not due to the Meibomian lipids alone, but is more likely to be due to a complex interaction between components of the aqueous and the Meibomian lipids.