| Diaphragm | Which part of the light microscope controls the intensity of light entering the viewing area? |
| Crystal violet, iodine solution, alcohol, safranin | What is the correct order of gram-staining |
| Gram Positive | Which bacteria appears purple-violet colour after staining? |
| Mordant | In Gram-staining, iodine is used as a? |
| Used as a fixative prior to staining in light microscopy | Heat |
| To reduce the number of bacteria on a dish to a know factor, in order to count population size | Serial Dilution |
| No. of Bacteria= colony number/(dilution rate x ml of sample) | Calculations for counting no. of bacteria. |
| Provides well segregates colonies. All bacteria grow from a single parent cell (isolated, no contamination). Creates a pure culture. | Streak plating |
| Done after incubation. Only chose plates with 30-300 CFU’s | Counting |
| Colony forming Unit. Used to estimate the number of viable bacteria or yeast. Shown as CFU per g/ml/cm2 etc. | CFU |
| Measurement of the number od bacterial cells per ml, g, cm3 etc.. | Bacterial Enumeration |
| Involve counting cells that can be cultured and/or metabolically active | Viable Counts |
| Counting all cells: dead, inactive and alive | Total Counts |
| Counting actual cells of colonies | Direct method of enumeration |
| Estimate numbers based on call mass, spectroscopy or statistical methods | Indirect method of enumeration |
| Used for direct and viable counting | Standard plate count |
| Used for direct and total counting | Fluorescent staining and microscopy |
| Used for indirect and viable counting | MPN |
| Used for indirect and tota counting | Spectroscopy |
| Measuring amount of light that passes through a liquid culture using a spectrophotometer and estimated number of cells from the light that passes through | Spectroscopy |
| Make statistical estimates by patten growth in liquid culture media | MPN |
| Used in serial dilution (saline) | Ringers solution |
| Between 30 and 300 | Number of colonies when enumeration |
| Inhibits the growth of some bacteria while selecting for the growth of others | Selective media |
| Selective media. Dyes inhibit Gram +ve bacteria and selects Gram -ve. Most GI tract infections caused by Gram -ve. | Brilliant Green Agar |
| Eosin Methylene Blue. Selective media. Dyes inhibit Gram +ve bacteria and selects Gram -ve. Most GI tract infections caused by Gram -ve. | EMB |
| Differentiates between different organisms growing on the same plate | Differential Media |
| Differential Media. Use to differentiate between different types of streptococci (E.g. Alpha, Beta and Gamma haemolytic streptococci) | Blood Agar Plates |
| Alpha= incomplete lysis of RB.> Beta= complete lysis. Differential media used. | Alpha, Beta and Gamma Haemolytic streptococci |
| Selective AND Differential Media. Used to identify Staphylococcus aureus. High salt conc. pH indicator. | Mannitol Salt Agar |
| Selective AND Differential Media. Identifies salmonella. Contains bile salts, crystal violet, lactose, pH indicator. | MacConkey’s Agar |
| A x 10b= log (A x 10b) =(log A) x (log10b)*=log A+ b | Log Value Calculation |
| Selective media for staphylococcus | Baird Parker Agar |
| Selective media for yeast | Malt Extract Agar |
| Selective media | Brilliance salmonella agar |
| Selective media for bac. Cereus | Brilliance Bacillus cereus agar |
| Selective media for pseudomonas | Pseudomonas’s selective agar |
| Crustal violet | Primary stain (in gram staining) |
| Heat them iodine | Fixative (in gram staining) |
| Acetone | Decolouriser (in gram staining) |
| Safarin | Counterstain (in gram staining) |
| For viewing the object. X 10 magnification | Ocular lens (microscope) |
| Adjusts and holds the eyepiece (custom for each user) | Body Tube (microscope) |
| Holds the objective lens- rotates to allow different lens to be chosen | Nose piece (microscope) |
| 4 different lenses. X10, x100, x40, oil immersion lens (for mineral oils) | Objective lens (microscope) |
| Objective lens x ocular lens | Total magnification (microscope) |
| Holds the slide and therefore sample in place | Object holder/mechanical stage clips (microscope) |
| used to vary the intensity and size of the cone of light that is projected upward into the slide | Iris or Diaphragm (microscope) |
| The purpose of the condenser lens is to focus the light onto the specimen | Condenser lens (microscopy) |
| Moves object horizontally. Front to back, left to right | Stage controls |
| Works with fine focus. Moves object up and down rapidly to get object into view | Rough/coarse focus |
| Moves object up and down finely/smoothly. Gets sample into focus after coarse focus used. | Fine/focus |
| is the use of certain growth media to favour the growth of a microorganism over others. E.g.. Media with a high salt concentration will select for halophiles | Enrichment media |
| =log (A x 10^b)
=(logA) x (log 10^b)
=log (A+B)
because log10=1 | A x 10^b |
