5 steps in procedure for serological pipettes
- Choose smallest pipette suitable for volume you intend to deliver
- Double check using correctly labelled pipette for liquid you dispensing, to avoid cross contamination
- Attach pipette to pump or bulb
- Draw liquid into pipette slowly
- Dispense liquid into receiving container slowly
What are serological pipettes used for?
To accurately dispense volumes of liquids.
Two warnings for serological pipette
- Numbers start with 9 on bottom and count to 0 on top.
2. Look out for decimal places
What are Pasteur pipette use for
Dispense liquids when accuracy less important and gently mix liquids by pipetting in and out
4 procedure steps to Pasteur pipette
- Double check using correctly labelled pipette for liquid you dispensing, to avoid cross contamination
- Attach pipette to pump or bulb
- Draw liquid into pipette slowly
- Dispense liquid into receiving container slowly
Why prepare wet mounts on glass slides?
To spread a sample thing enough to view clearly under microscope
4 step procedure in preparing wet mount
- Place small drop of sample in middle of glass slide
- Gently place one edge of cover slip on slide so slip touches sample
- Gently lower opposite edge of cove slip using pemcil or Pasteur pipette to avoid forming bubbles under slip
- Use tissue to soak up any excess liquid until slip does not move when slide titled
Purpose to iodine test
To determine whether a sample contains starch
3 steps for iodine test
- Obtain iodine and clean dry spot plate with many depressions on it
- Add 2-3 drops of sample to one of depressions and add 2 drops of iodine sln to same depression
- Observe any changes in colour. Iodine bonds with starch to produce w deep purplish blue colour
Purpose to cheesecloth
Filter out large solids while allowing liquids and smaller particles to pass thru
3 steps in cheesecloth procedures
- Label clean test tube and place in rack
- Place funnel on top of tube and place cheesecloth top of funnel
- Pour sample slowly in middle of cloth, wait for sample to pass through, into tube
Disadvantage of cheescloth
Cloth absorb 4.5 mL of liquid. Make sure babe enough homogenate to get enough filtrate despite absorption
Parts of compound microscope
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