lab exam 1-6

What is the lab benches dissinfected with before and after each lab?

10% bleach

Where should culture tubes never be placed?

Never placed in the lab bench drawers

What should prepared slides and microscope objective lens be cleaned with?

Lens paper moistened with 5% Windex after oil immersion use

Where are staining solutions poured?

Into the chemical waste container

How is the total magnification of a compound microscope calculated?

multiplying the magnification of the ocular lens (eyepiece) by the magnification of the active objective lens

Low power TM

100x

High power TM

400x

Oil immersion TM

1000x

Lab 1 and 2 was on?

Suvery of microorganisms

What was used in Labs 1 and 2 Suvery of Microorganisms?

Bacteria, cyanobacteria, fungi, algae, protozoa

Labs 3 and 4 were on?

Cytological techniques

What are the 7 cytological techniques?

Negative stain, smear prep, simple stain, gram stain, acid-fast stain, spore stain, capsule stain

What were the five prepared slides used within lab 3 and 4?

bacterial flagella, bacterial spores, capsule stain, acid-fast stain, and metachromatic granules

What technique has to be maintained for all procedures in the cytological techniques?

Aseptic/sterile technique has to be maintained for all procedures of these lab exercises

When water is mentioned as an ingredient, what is used for all procedures?

Sterile DI H20 is used for all procedures where water is mentioned as an ingredient

What organisms were used for smear preparation?

liquid and solid media of b. megaterium, s epidermidis, e.coli

In simple and acid-fast stain, what are the smears stained with?

methylene blue (Loeffler’s)

What are smears stained with in gram stain?

Crystal violet

What are stains dried with after being stained?

Bibulous paper

What are smears in spore stain stained with?

5% malachite green

What is lab 6?

Enumeration of microorganisms

What are the 3 techniques of enumeration of microorganisms?

Direct count with hemocytometer, viable count (plate count), turbidity study with spectrophotometer (growth determination by optical density)

What organism was used for the direct count by hemacytometer?

pure yeast (saccharomyces cerevisiae)

How do you calculate the actual cell number per ml?

Total cell count per 5 boxes x 5 × 10^4 = cells per ml of solution

What is the cell number per ml equal to?

The cell number per ml is equal to total cell number in 25 larger boxes x 10^4

What organisms are used in the viable count - plate count?

pure yeast (saccharomyces cerevisiae)

What is viable count measured by?

CFUs (colony forming units) per ml

What are colony forming units?

cells that are viable, capable of reproduction and colony formation

What does viable count =?

Viable count (cell number/ml) = the plate count x dilution factors

To determine percent viability from a CFU count, what calculation is used?

Colony count/cells per ml plated x 100% = percent viability

What is the other equation to determine percent viability from CFU count?

viability = viable count / direct count x 100%

What organisms were used in the turbidity study?

yeast (saccharomyces cerevisia)

What is optical density measurement?

measured as % absorbance