BIOL 2021 Lecture Notes - Immunocytochemistry, Rhodamine B, Green Fluorescent Protein
Document Summary
Lecture 1: introduction and how to visualize cells. Biology is a contingent science (based on the past) Biology emphasizes the importance of evolutionary history: evolution is a tinker. Mechanisms appear to be arbitrary we don"t understand the controls i. e. why does it do this? it just does. Cell communication (signal proteins/hormones: calcium, junctions (tight, gap, desmosomes) Cell division control, oncogenes and the cell cycle. Cell walls in: bacteria, fungi, plants: noted that chemically, they are all different. Light microscopy: image focused with the condenser: transmitting light through the specimen, bright field is better for coloured specimens. Kill it, thin section, stain it: figure 9. 8. Phase contrast microscopy good to make transparent cells visible: thermoforms. Fluorescence excited by one wavelength, then emits at another wavelength: dyes like dapi binds to dna. Chemicals will absorb a certain colour, then will emit light with a lower energy (higher wavelength) Rhodamine b will absorb green and emit red light (620nm)