MAIN BUTTONS FOR ALL THINGS LAB PRACTICAL 1 (20%) - the first
Exam:
Lecture Material
*During the first 2 classes PRINT/BIND/OBTAIN your first LABORATORY GUIDE instructional materials:
GENERAL MicroDropbox Link (CLICK HERE)
GENERAL MicroDropbox Link (CLICK HERE)
LP1 Ch 9 Origins Video & Worksheet
*Prepare Your 1st 11 Lab Projects
All slides MUST be WASHED with Bon Ami AND TESTED for proper cleanliness before Smear Preparation. This is because even pre-washed boxed slides are sprayed with oil to keep the glass slides from sticking together. OIL PREVENTS the attachment process of SMEAR PREPARATION and must be removed!
To do this you make a thick dry "paste" of the Bon Ami and rub it over the slide at least 2X and rinse well. Next you TEST to see if the slide is clean by putting it under running water, removing it, counting to 5 and seeing if the water SHEETS OFF the slide or if there is "retraction" or bubbling of the water around the edges or anywhere on the slide similar to water "beading-up" on a freshly waxed car after a rain. If you see retraction or beading your must wash the slide and rinse and test it again.
If you use a dirty slide for a Smear and Stain the slide will sluff-off the bacteria and NOTHING will stick or stain and you will see NOTHING!
The above button is a COMPLETE START to the LP1 SMEARS & the major Stains... Smears are done to attach bacteria to a slide in a gentle manner so that they can be colorized for viewing because they are colorless...an extra benefit (but not the purpose of a smear is that it kills the bacteria)
INTERPRETATION OF STAINED SLIDES - HINTS - READ!
The NEGATIVE STAIN is NOT a STAIN!
FOCUSING HINTS/HELP!
For each stain there is a specific "PROBLEM" organism or 2 that makes interpretation difficult. ABOVE review this link to see the PROBLEM ORGANISMS for each of our 3 major stains.
Below find links to practice using photos taken in class. Click on the each photo to find a discussion about what stain, the shape of the microbe and problems if any with "reading" the stain.
NOTE: 1/3 of the LP1 EXAM is reading photos of problem stains. You must tell me NOT THE NAME of the MICROBE but the shape, the name of the stain, whether the microbe stained positive (+) or negative (-) on that stain AND why it stained in that manner... THIS IS THE MOST MISSED PORTION OF THE LP1 EXAM
READING A STAIN! (CLICK HERE)
Most of these cards are done well but, for the Staining better ones are found under SMEARS button above....
HINTS AND TEST QUESTIONS FROM LAB:
- The most important step and most common error in Smear Prep AND Staining is "FAILURE TO PROPERLY WASH AND TEST A SLIDE!
- The second (2nd) most common error in making a Smear Prep (esp from Agar) is putting TOO MUCH Bacteria INTO THE WATER and failing to spread the mix over the entire surface of the slide before air drying/heat fixing!
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The GREATEST SIN in Microbiology is "CHUNKING" the agar!
EVIL = MICRO HELL!
- Prep of a Smear from Agar - dilutes the bacteria in a drop of water
- Prep of a Smear from Broth - concentrates the bacteria so that they may be seen as they are too dispersed in the fluid. COATINGS according to the "e" test are require for a smear from broth
- Water is required to be added to a slide for prep of a smear from agar
- You must never lay down a loop, cap, or tube... they must be in your hand or in a test tube rack or test tube block at ALL TIMES
- LOOPS/NEEDLES must ALWAYS be heated to RED hot their entire length at once and then cooled for 5 seconds before use
- SHARPIE marks & labels go ONLY on the BOTTOM of a clean slide; if you put them on the top, movement of the loop strips the Sharpie mark off and it will float during focusing - you will see floating black shapes
- YOU must be in gloves/lab coat (with hair tied up) and have disinfected your table top to work with microbes