Microscopy and Staining

Important words and concepts from Chapter 3, Black, 2002 (3/28/2003):

by Stephen T. Abedon (abedon.1@osu.edu) for Micro 509 at the Ohio State University

Course-external links are in brackets

Click [index] to access site index

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(1) Chapter Title: Microscopy and Staining

(a) "Microscopy is the technology of making very small things visible to the human eye."

(b) See Figure 3.2, Relative sizes of objects, for a look at the relative sizes, on a log scale, of microorganisms and other objects of biological relevance

(d) Note that a compound light microscope is only capable of viewing down to the smallest common bacteria (i.e., Chlamydia in the figure) whereas the human eye can see down to only the largest of individual cells

(e) See additionally: [microscopy (Google Search)] [history of the light microscope (Thomas E. Jones)][microscope glossary (Microbiology 12 - City College of San Fransico)] [Standard microscopy terminology (Center for Interfacial Engineering - University of Minnesota)] [Microscopy links (Light Microscopy Forum - Ron Neumeyer)] [index]

INTRODUCTION TO COURSE, NOTES, AND MICROORGANISMS (SUPPLEMENT)

(2) Studying tips:

(a) Throughout this course (i.e., these notes) I will be doing my best to supply you with links to supplemental material found on the World Wide Web

(i) If you have additional interest in presented material or need additional exposure to concepts, consider following these links (on line, of course)

(ii) I will regularly include Google searches that may be followed for abundant additional information on material—however, always keep in mind that your first, best reference will usually be your text book

(iii) There also exists an index to this site called MicroPort that is found at http://www.phage.org/microbiology.htm or by pressing [index] throughout these notes

(b) Read over assigned material in your text before coming to lectures

(i) Read your text well so that, minimally, you have made an attempt at understanding the presented concepts

(i) Read lecture notes well so that you have made an attempt at understanding the presented concepts

(ii) Make an effort to memorize the supplied vocabulary

(d) Come to class prepared to ask questions

(e) After class, organize the material, integrating the notes that you take during class

(f) REMEMBER, CLASS ONLY MEETS TWICE A WEEK SO BLOWING OFF A LECTURE OR NOT STUDYING PRIOR TO AND AFTER A LECTURE IS EQUIVALENT TO BLOWING OFF HALF OF A WEEK OF STUDYING

(g) Study for the first exam in this course harder than you have ever studied for an exam before

(i) Triage the material you will be studying such that you don’t waste your time studying the material you already know/understand

(ii) Make sure that you have extensively been through the material and have organized it before you begin to study

(iii) Don’t put off your studying to the last minute

(iv) Don’t count organizing and learning your material as exam study time—studying for an exam involves making sure that you have memorized and can lucidly regurgitate the material, not simply becoming familiar with it

(v) Simply reading over notes again and again is not necessarily equivalent to doing the hard work of learning

(h) Don’t forget that labs are worth a good chunk of your grade

(i) Don’t blow off labs

(ii) Read labs before you come to laboratories and as you are doing them

(iii) Also read your lab schedule for tips on how to do labs

(iv) Labs are much (much, much) easier to do when you are familiar with them; I will be able to tell when you are unfamiliar with labs; I will reserve the right to quiz on lab preparation if I get the impression that students are coming to laboratories unprepared

(v) Answer questions and make notes while the material is still fresh in your mind

(i) For tips on how to study for microbiology, see: [microbiology and "study tips" (Google Search)] [microbiology study tips (need to skip down a bit to find) (Gary E. Kaiser)]

(j) Links to other on-line microbiology courses (and course-like sites): [microbiology and course (Google Search)] [Microbiology Webbed Out (Kenneth Todar)]

(k) Microbiology link collections can be found at: [microbiology links (Google Search)]

(l) For an overview of chemistry, click here.

(3) What is Microbiology?

(a) Microbiology is "the study of microbes, organisms so small that a microscope is needed to study them."

(b) Microbiology, as a science, may be differentiated along organism lines ("the variety of kinds of microbes") and in terms of techniques and goals ("the kind of work microbiologists do")

(c) [microbiology (Google Search)] [index]

(4) The variety of kinds of microbes (microbes, microorganisms)

(a) Microbes are typically (but certainly not always) either unicellular organism (e.g., bacteria) or acellular "organisms" (e.g., viruses)

(b) Typically a microbiologist will differentiate microbes into the following categories:

(i) bacteria

(ii) algae

(iii) fungi

(iv) viruses

(v) protozoa

(vi) helminths

Supplemental Material – Types of Microorganisms & their General Properties
organism:	types:	description:	Nutrition type (-trophs):	durable state:	some diseases:
algae:	brown, red, green, diatoms, dinoflagellates, euglenoids	photosynthetic aquatic eucaryotes, cell walls, unicellular and multicellular	photoauto-	---	---
bacteria:	eubacteria, archaeabacteria, Gram-negative, Gram-positive, acid fast, cyanobacteria	procaryotes, absorbers, wet conditions, animal decomposers, cell walls, unicellular	chemohetero- photohetero- chemoauto- photoauto-	endospores (some)	tetanus, botulism, gonorrhea, chlamydia, tuberculosis, etc., etc., etc.
cyano-bacteria:	blue-green algae	photosynthetic aquatic procaryotes, green lake scum, cell walls	photoauto-	---	---
fungi:	yeasts (unicellular fungi), molds (filamentous fungi)	eucaryotes, absorbers, dry conditions, plant decomposers, cell walls, ~100 human pathogens	chemohetero-	spores	mycoses: candida, ringworm, athlete's foot, jock itch, etc.
helminths:	Flatworms (platyhelminths), roundworms (nematodes)	metazoan (multicellular animal) parasites, engulfers and absorbers	chemohetero-	---	tape worm, trichinosis, hook worm, etc.
protozoa:	Unicellular and slime molds, flagellates, ciliates	eucaryotes, parasites, engulfers and absorbers, wet conditions, no cell wall, ~30 human pathogens	chemohetero-	cysts (some)	malaria, giardiasis, amoebic dysentery, etc.
viruses:	Enveloped, non-enveloped	acellular, obligate intracellular parasites	not applicable	virion particles, encased in durable state of host	common cold, flu, HIV, herpes, chicken pox, etc.

(5) Bacteria (chapters 4, 6, 7, 8, 9)

(a) The bacteria have the following characteristics:

(i) Relatively small

(ii) Single-celled

(iii) No nucleus or other membrane-bound organelles

(iv) Simple morphologies

(v) Primarily synthesizers or absorbers (i.e., not engulfers)

(b) Most bacteria do not cause human diseases, but most infectious diseases are caused by bacteria (and viruses)

(d) [bacteria (Google Search)] [index]

MICROSCOPY – SOME THEORY

(2) Resolution

(a) The object of microscopy is not just to increase magnification, but to do so while retaining sufficient resolution

(b) Resolution is the ability to see two items as two separate things, i.e., two dots as two separate dots

(c) The resolution a microscope is capable of achieving is the smallest distance between two dots such that the two dots may be observed (resolved) as separate entities

(d) In less technical terms, lower resolution means an increased degree of fuzziness, i.e., less focusable [sic?] specimens

(e) See Figure 3.5, Resolution

(f) [microscope resolution (Google Search)] [resolution (Standard Microscopy Terminology)] [index]

(3) Wavelength [l]

(a) Viewing things through a microscope usually means passing something (e.g., light) through a specimen (an object)

(b) The shorter the wavelength, the higher the resolution theoretically one can achieve with a microscope

(d) Blue light, for example, has a shorter wavelength than red light (blue light is also more energetic than red light)

(e) See Figure 3.4, The electromagnetic spectrum

(f) Thus, a light microscope that was limited to employing blue light can theoretically achieve a higher resolution than an otherwise similar light microscope that employs only red light (or all wavelengths of visible light)

(g) [wavelength and light (Google Search)] [wave length (Standard Microscopy Terminology)] [index]

(4) Electrons

(a) Light is not the only thing that has a wavelength

(b) All objects have an associated wavelength, and the larger the object, the shorter the wavelength

(d) Electrons thus have much smaller wavelengths than light (especially visible light) so consequently a microscope that employs electrons rather than light has a much higher theoretically (and actually) achievable resolution

(e) [electrons and waves, electron and waves (Google Search)] [index]