Lab Exercise #4: Intro to lab safety Microscopes

Safety info Read the two sheets (green and pink) Read the two sheets (green and pink) Sign the yellow sheet Sign the yellow sheet Under 18? Please see me. Under 18? Please see me.

Lab safety First aid kit at the front First aid kit at the front Fire extinguisher at the back Fire extinguisher at the back Eye wash at sink Eye wash at sink Showers in the back Showers in the back

Lab Safety No eating or drinking in lab No eating or drinking in lab Clean up rule: Clean up rule: –It is your responsibility to clean up after yourself and put everything back like you found it

Lab clean up Put models back, like you found them Put models back, like you found them Put microscopes back Put microscopes back Put slides back in the proper box Put slides back in the proper box

Lab clean up Dispose of other items as follows: Dispose of other items as follows: –Paper towels go in the trash –Broken glass and slide cover slips go in “broken glass” –Biological waste goes in red bucket –Empty slides get rinsed, dried, and returned to box –Dissection tools: put in wash –Wipe down your bench area when done

Lab 4: Intro to microscopes Microscopic anatomy: Microscopic anatomy: –Cells –Tissues

Who cares? Medically, microscopes are used for pathology, the study of disease. Medically, microscopes are used for pathology, the study of disease. –If a disease is suspected, a tissue sample is taken (biopsy, blood) or a cell sample (pap test) –Pathologist or technician looks for abnormal cells, etc.

Who cares? Scientifically, microscopes are used to study cells and tissues for all kinds of reasons (e.g. brain damage research) Scientifically, microscopes are used to study cells and tissues for all kinds of reasons (e.g. brain damage research)

What about us? Educationally, microscopes are the only way to truly learn about the microscopic organizations of cells and tissues. Educationally, microscopes are the only way to truly learn about the microscopic organizations of cells and tissues. Knowing how to use a microscope is a great skill to have, no matter what medical or biology subfield you are involved in. Knowing how to use a microscope is a great skill to have, no matter what medical or biology subfield you are involved in.

Compound microscope Uses multiple lenses to achieve larger magnification Uses multiple lenses to achieve larger magnification

Compound microscope Key parts: Key parts: –Eyepieces (ocular objectives) –Arm –Base –Objectives –Stage (and stage clips) –Stage controls –Coarse and Fine focus –Condenser –Iris diaphragm –Light

How to carry a microscope Two hands, one on arm, one on base Two hands, one on arm, one on base Put your microscope back in the numbered cubby it came from Put your microscope back in the numbered cubby it came from

Properties Compound: occulars = 10x, objectives = 4x, 10x, 40x. Multiply to get total magnification Compound: occulars = 10x, objectives = 4x, 10x, 40x. Multiply to get total magnification Parafocal Parafocal Inverted optics Inverted optics Field of view Field of view

How to use Start on lowest power (condenser up) Start on lowest power (condenser up) Load slid into clip Load slid into clip Look thorough oculars, adjust (one image) Look thorough oculars, adjust (one image) Focus (coarse) Focus (coarse) Find region of interest, go to higher power Find region of interest, go to higher power Focus (fine) Focus (fine) **Adjust light level and iris diaphragm as needed (less light at low power)

Careful When using higher power objectives, it is easy to break slides. When using higher power objectives, it is easy to break slides.

Making a wet mount slide Put drop on slide Put drop on slide Put on over slip at an angle Put on over slip at an angle

Activities Get scope and set up Get scope and set up Make pond water wet mount slide and observe (to practice focusing) Make pond water wet mount slide and observe (to practice focusing) Letter “e” slides (prepared). Letter “e” slides (prepared). Thread slides (Careful, they’re thick). Determine order of threads. Thread slides (Careful, they’re thick). Determine order of threads. Grid slide: count and calculate – measure at lowest power, use this figure to calculate answers at higher power (table 4.1). Grid slide: count and calculate – measure at lowest power, use this figure to calculate answers at higher power (table 4.1). Clean up Clean up

Clean up Wash/dry fresh mount slides, put back Wash/dry fresh mount slides, put back Cover slips in lab glass container Cover slips in lab glass container Put prep’d slides back into right box Put prep’d slides back into right box Clean off lens with lens paper and lens cleaner ONLY Clean off lens with lens paper and lens cleaner ONLY Clean off stage and return scope Clean off stage and return scope Clean up your area Clean up your area

Turn in Lab 4 report due next lab period (rip out or copy). Lab 4 report due next lab period (rip out or copy). Turn in parts C and D and Table 4.1 your answers for the order of the threads in activity 3 Turn in parts C and D and Table 4.1 your answers for the order of the threads in activity 3

For table 4.1 Ignore “working distance” column Ignore “working distance” column Find the field diameter for the lowest magnification by counting the number of grid squares that you can see across the field of view (1 sq = 1mm) Find the field diameter for the lowest magnification by counting the number of grid squares that you can see across the field of view (1 sq = 1mm) CALCULATE the field diameter for the other magnifications by using the formula on p. 42 CALCULATE the field diameter for the other magnifications by using the formula on p. 42

Field diameter F.D. lens B = F.D. lens A x total magnification lens A total magnification lens B total magnification lens BExample: F.D. med power = F.D. at low power x total low power total magnification med power total magnification med power = 10mm X 40x = 10mm X 40x 100x 100x = 4mm = 4mm