REMOTE LAB ACTIVITY
SUBJECT SEMESTER: ________________
TITLE OF LAB: Histology - Epithelial Tissue
Lab format: This lab is a remote lab activity.
Relationship to theory (if appropriate): In this lab you will learn the underlying principles behind the
histological study of tissues.
Instructions for Instructors: This protocol is written under an open source CC BY license. You may use
the procedure as is or modify as necessary for your class. Be sure to let your students know if they
should complete optional exercises in this lab procedure as lab technicians will not know if you want
your students to complete optional exercises.
Instructions for Students: Read the complete laboratory procedure before coming to lab. Under the
experimental sections, complete all pre-lab materials before logging on to the remote lab. Complete
data collection sections during your online period, and answer questions in analysis sections after your
online period. Your instructor will let you know if you are required to complete any optional exercises in
this lab.
Remote Resources: Primary – Microscope, Secondary – Histology slide set.
CONTENTS FOR THIS NANSLO LAB ACTIVITY:
Learning Objectives..................................................................................................
Background Information .........................................................................................
Equipment ...............................................................................................................
Experimental Procedure .........................................................................................
Pre-lab Exercise 1: Simple Squamous Epithelium ..................................................
Exercise 1: Simple Squamous Epithelium ...............................................................
Pre-lab Exercise 2: Simple Cuboidal Epithelium .....................................................
Exercise 2: Simple Cuboidal Epithelium .................................................................
Pre-lab Exercise 3: Simple Cilated Columnar Epithelium ......................................
Exercise 3: Simple Cilated Columnar Epithelium ..................................................
Pre-lab Exercise 4: Stratified Squamous Epithelium ..............................................
Exercise 4: Stratified Squamous Epithelium ..........................................................
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Summary Questions ................................................................................................. 6
Preparing for this NANSLO Lab Activity .................................................................. 7 - 21
LEARNING OBJECTIVES:

Overview of histology and tissue types
1. Define the term histology.
2. List four major tissue types.
3. Contrast the general features of the four major tissue types.

Microscopic anatomy, location, and functional roles of epithelial tissue
1. Classify the different types of epithelial tissue based on distinguishing structural
characteristics.
2. Describe locations in the body where each type of epithelial tissue can be found.
3. Describe the functions of each type of epithelial tissue in the human body and correlate
functions with structure for each tissue type.
4. Identify the different types of epithelial tissue using proper microscope technique.
BACKGROUND INFORMATION:
A living organism is composed of a variety of cells of different sizes, shapes, structures and
specialized functions. Cells of similar type are usually organized into groups. A group of cells
with similar size, shape, structure and function form a tissue, and there are four general classes
of tissues. These classes are: epithelial, connective, muscle, and neuronal. In this lab we will
use histology to examine four epithelial tissues.
Histology1 is the branch of biology concerned with the composition and structure of plant and
animal tissues in relation to their specialized functions. The terms histology and microscopic
anatomy are sometimes used interchangeably, but a fine distinction can be drawn between the
two studies. The fundamental aim of histology is to determine how tissues are organized at all
structural levels, from cells and intercellular substances to organs.
Epithelial tissues are composed of cells that make up the body’s outer covering and the
membranous covering of internal organs, cavities, and canals. Epithelium2 is a layer of cells
closely bound to one another to form continuous sheets covering surfaces that may come into
contact with foreign substances. Epithelium occurs in both plants and animals. In animals,
outgrowths or in growths from these surfaces form structures consisting largely or entirely of
cells derived from the surface epithelium. In this way the central nervous system, the sensitive
surfaces of special sense organs, glands, hair, nails, and other structures all originate. The
epithelial cells possess several microscopic characteristics:
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The cell outline is clearly marked.
The nucleus large and spherical or ellipsoidal.
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The cytoplasm of the cell is usually large in amount.
The cytoplasm often contains large numbers of granules.
Epithelium may be protective, absorptive, or secretory. It may produce special outgrowths
(hairs, nails, or horns on animals), and manufacture chemical material (e.g., keratin), in which
case the whole cell becomes modified. In other instances it contains fat droplets, granules of
various kinds, protein, mucin, watery granules, or glycogen. In a typical absorbing cell, granules
of material are absorbed. A secreting cell forming specific substances stores them until they are
utilized—e.g., fat, in sebaceous and mammary glands; enzymes in salivary and gastric glands.
Epithelial tissues are classified based on the shape of the cells and the number of layers. In the
following exercises, we will be looking at representatives of four of these epithelial classes.
References:
1. "histology." Encyclopedia Britannica.
http://www.britannica.com/EBchecked/topic/267172/histology (22 April, 2014)
2. "epithelial." Encyclopedia Britannica.
http://www.britannica.com/EBchecked/topic/190379/epithelium (22 April, 2014)
EQUIPMENT:




Paper
Pencil/pen
Slides
o Simple squamous epithelium slide
o Simple cuboidal epithelium slide
o Simple ciliated columnar epithelium slide
o Stratified squamous epithelium
Computer with Internet access (for the remote laboratory and for data analysis)
EXPERIMENTAL PROCEDURE:
Once you have logged on to the remote lab system, you will perform the following laboratory
procedures. See Preparing for the Microscope NANSLO Lab Activity below.
During the study of each type of epithelial tissue, you are required to photograph and label a
representative sample of each tissue type. You should begin with your microscopic examination
of the tissue slide using the 4X objective to give you a perspective of the entire structure. This
is very important since sometimes more than one tissue type is often present on each slide. All
observations should be made using the 40X or 60X objective lens (whichever gives you the best
image).
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PRE-LAB EXERCISE 1: Simple Squamous Epithelium
Pre-lab Question:
1. How many layers of cells do you predict the simple squamous epithelium has? And what is the
cell's shape?
EXERCISE 1: Simple Squamous Epithelium
Data Collection:
2. Select the simple squamous epithelium slide from the microscope interface. Using the 10X
objective, locate the tissue sample and bring it into focus.
3. Carefully work your way through all the objectives, focusing with each one until you reach the
40X or 60X objective and capture an image of simple squamous epithelium. Insert your image
below.
Analysis:
4. Using your image from Exercise 1, question 3, label the three different parts of a cell (nucleus,
cytoplasm and cell membrane) and the basal membrane.
5. Based on your observation, describe the shape of cells and indicate the number of layers in this
tissue type.
6. Are your results in correlation with what you have predicted earlier?
7. Discuss the advantage of having a simple squamous epithelium in the lungs (hint: think of
respiratory gases exchange).
PRE-LAB EXERCISE 2: Simple Cuboidal Epithelium
Pre-lab Question:
1. How many layers of cells do you predict the simple cuboidal epithelium has? And what is the
cell's shape?
EXERCISE 2: Simple Cuboidal Epithelium
Data Collection:
2. Select the simple cuboidal epithelium slide from the microscope interface. Using the 10X
objective, locate the tissue sample and bring it into focus.
3. Carefully work your way through all objectives, focusing with each one until you reach the 40X
or 60X objective and capture an image of the simple cuboidal columnar epithelium. Insert your
image below.
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Analysis:
4. Using your image captured in Exercise 2, question 3, label the 3 different parts of a cell (nucleus,
cytoplasm, and cell membrane), and the basal membrane.
5. Based on your observation, describe the shape of cells and indicate the number of layers in the
tissue type.
6. Are your results in correlation with what you have predicted earlier?
7. Discuss the advantage of having a simple cuboidal epithelium in the kidneys.
PRE-LAB EXERCISE 3: Simple Ciliated Columnar Epithelium
Pre-lab Questions:
1. How many layers of cells do you predict the simple ciliated columnar epithelium has? And what
is the cell's shape?
EXERCISE 3: Simple Ciliated Columnar Epithelium
Data Collection:
2. Select the simple ciliated columnar epithelium slide from the microscope interface. Using the
10X objective, locate the tissue sample and bring it into focus.
3. Carefully work your way through all the objectives, focusing with each one until you reach the
40X or 60X objective and capture an image of the simple ciliated columnar epithelium. Insert
your image below.
Analysis:
4. Using your image from Exercise 3, question 3, label the three different parts of a cell (nucleus,
cytoplasm, and cell membrane) and the basal membrane.
5. Based on your observation, describe the shape of cells and indicate the number of layers in this
tissue type.
6. Are your results in correlation with what you have predicted earlier?
7. Discuss the advantage of having a simple ciliated columnar epithelium in the epididymis.
PRE-LAB EXERCISE 4: Stratified Squamous Epithelium
Pre-lab Question:
1. How many layers of cells do you predict the stratified squamous epithelium has? And what is
the cell's shape?
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EXERCISE 4: Stratified Squamous Epithelium
Data Collection:
2. Select the stratified squamous epithelium slide from the microscope interface. Using the 10X
objective, locate the tissue sample and bring it into focus.
3. Carefully work your way through all the objectives, focusing with each one until you reach the
40X or 60X objective and capture an image of the stratified squamous epithelium. Insert your
image below.
Analysis:
4. Using your image from Exercise 4, Questions 3, label the three different parts of a cell (nucleus,
cytoplasm, and cell membrane) and the basal membrane.
5. Based on your observation, describe the shape of cells and indicate the number of layers in this
tissue type.
6. Based on your investigation, do you accept or reject your initial hypothesis? Use evidence
gathered to explain why you would accept or reject your initial hypothesis.
7. Discuss the advantage of having this type of tissue in the esophagus rather than the simple
squamous epithelium you observed earlier.
SUMMARY QUESTIONS
1.
2.
3.
4.
5.
What are the two criteria used to classify the different types of epithelial tissue?
Where is the ciliated epithelium commonly found? What unique function does it provide?
Where are goblet cells commonly located? What is their function?
Where would epithelium containing microvilli most likely be located and why?
Brandon sprained his ankle in a mountain biking race. Based on the definition of a sprain, what
specific histological type of tissue has Branson injured?
6. Explain why you would expect this type of tissue to have a high or low mitotic index.
7. How will the mitotic index affect the rate of healing of Brandon's injury?
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PREPARING FOR THIS NANSLO LAB ACTIVITY:
Read and understand the information below before you proceed with the lab!
Scheduling an Appointment Using the NANSLO Scheduling System
Your instructor has reserved a block of time through the NANSLO Scheduling System for you to complete
this activity. For more information on how to set up a time to access this NANSLO lab activity, see
www.wiche.edu/nanslo/scheduling-software.
Students Accessing a NANSLO Lab Activity for the First Time
You must install software on your computer before accessing a NANSLO lab activity for the first time.
Use this link to access instructions on how to install this software based on the NANSLO lab listed below
that you will use to access your lab activity – www.wiche.edu/nanslo/lab-tutorials
1. NANSLO Colorado Node -- all Colorado colleges.
2. NANSLO Montana Node -- Great Falls College Montana State University, Flathead Valley
Community College, Lake Area Technical Institute, and Laramie County Community College.
3. NANSLO British Columbia Node -- Kodiak College.
Using the Microscope for a NANSLO Remote Web-based Science Lab Activity
We've provided you with three ways to learn how to use the microscope for this NANSLO lab activity:
1. Read these instructions.
2. Watch this short video https://www.youtube.com/watch?feature=player_embedded&v=m7w9ssIgVdw.
3. Print off these instructions to read (PDF version of the instructions.)
NOTE: The conference number in this video tutorial is an example. See “Communicating with
Your Lab Partners” below to determine the toll free number and pin to use for your NANSLO lab
activity.
MICROSCOPE RWSL LAB INTERFACE INSTRUCTIONS
The Remote Web-based Science Lab (RWSL) microscope is a high quality digital microscope located at
the NANSLO Node. Using a web interface as shown below, you can control every function of the
microscope just as if you were sitting in front of it.
The equipment control software shown below is written using the LabVIEW software from National
Instruments. The user interface is presented as a LabVIEW control panel which will be referred to as the
lab interface for the remainder of the document.
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Figure 1: Remote Web-based Science Lab (RWSL) Microscope Lab Interface
COMMUNICATING WITH YOUR LAB PARTNERS
As soon as you have accessed this lab interface, call into the toll free conference number shown on the
control panel to communicate with your lab partners and with the Lab Technicians. Use the PIN code
noted to join your lab partners. Only one person can be in control of the equipment at any one time so
talking together on a conference line helps to coordinate control of the equipment and creates a more
collaborative environment for you and your lab partners.
GAINING CONTROL OF THE MICROSCOPE
Right click anywhere in the grey area of the lab interface and choose “Request Control of VI” from the
dialogue box that appears when multiple students are using the microscope at the same time,. After
you request control, you may have to wait a short time before you actually receive control and are able
to use the features on this lab interface.
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Figure 2: Selecting "Request Control of VI"
RELEASING CONTROL OF THE MICROSCOPE
To release control of the microscope so that another student can use it, right click anywhere in the grey
area of the lab interface and choose "Release Control of VI" from the dialogue box that appears.
Figure 3: Selecting "Release Control of VI"
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MICROSCOPE CONTROLS
The Stage Controls allow you to adjust the visual of the specimen that has been placed on the stage of
the microscope, select lenses with various magnifications, and select whether or not the condenser lens
is in the light beam. Below are more specific instructions on using these controls. When using the
arrows on this lab interface, click and hold the arrow until the desired effect is achieved or click and wait
to view the result before clicking again. Quick clicks on the arrows may cause the system to lock up.
Figure 4: Microscope Controls - Stage, Objective & Condenser
Stage Controls: Using the left and right and up and down arrows found to the right of the microscope
image in the Stage Control area, moves the microscope stage which holds the specimen. These arrows
allow you to precisely control the position of the specimen on the stage.
1. Use the "Right" and "Left" arrows to move the Stage so that you can view the specimen from
left to right.
2. Use the "Backward" and "Forward" arrows to move the Stage so that you can view the top,
middle or bottom of the specimen.
3. Use the "Up" and "Down" arrows to move the stage closer or farther away from the objective
lens to bring a specimen into focus. BE CAREFUL! Don't move the stage too close to the lens.
When selecting the button between the "Up" and "Down" arrows, you can toggle between “Coarse” and
“Fine” focus. When the button is dark green and “Coarse/Fine” is displayed to the right of the button,
the microscope is in “Coarse” focus. When the button is bright green and “Fine” is displayed, the
microscope is in “Fine” focus. Typically, you will start with coarse focus which moves the stage in large
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increments and then use fine focus to complete your final focusing as it moves the stage in smaller
increments. There is no difference between the course and fine focus when using the 60X objective
NOTE: When you click on these arrows, the specimen appears to move in the opposite direction. Since
the objective stays fixed, the image moves in the opposite direction of the stage. This is how these
controls work on most microscopes so the "feel" of the microscope is preserved over the web.
Figure 5: Right/Left & Backward/Forward Stage
Controls
Figure 6: Up/Down Stage Controls & Coarse/Fine
Focus Control
Objective: A microscope mounts an objective lens very close to the object to be viewed. Depending on
need, different lenses with different power will be used on the microscope. This microscope feature
multiple objectives, each with different power, mounted on a rotating turret. The larger the
magnification numbers the greater the magnification. For example, if a specimen is viewed through a
40X objective lens, the magnifier in that lens displays the specimen 40 times larger than an equivalent
view as seen by the unaided eye. Remember that the ocular or other lenses also add to the
magnification.
This microscope has five lenses – 4X, 10X, 20X, 40X, and 60X. Use the arrows below the objective lens
box that indicates the magnification of the current objective lens to move to a higher or lower
magnification lens. If you have activated the “Picture-in-Picture” Preset 2 (see below) you will be able to
see the objective lens move when you select a new magnification.
Condenser: The condenser controls whether or not the condenser lens is in the light beam. You want to
have the condenser OUT for the 4x objective but IN for all the others.
SELECTING A CASSETTE AND LOADING SLIDES ONTO THE STAGE
There are two tabs on the lab interface. When you first access the lab interface, the "Microscope" tab is
displayed by default. Click on the Slide Loader tab at the top of the screen to access the controls for the
Slide Loader robot. There can be up to four cassettes available on the Slide Loader. These cassettes are
used to store slides, and each can hold up to 50 slides. The cassettes available to you are dependent on
the lab activity to be completed. Once a cassette has been selected, you will use the drop-down list to
select your slides.
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Figure 7: Select the Slide Loader Tab to select a cassette and slides.
EXAMPLE OF HOW TO LOAD SLIDES
In this example, we have selected Cassette #1. Using the drop-down menu, we have selected "1:
Colored Threads Whole Mount." Then, we selected the "Load" button. A message indicates that the
slide is loading. Using the picture-in-picture camera, you can watch this happening. The robotics selects
the slide and places it on the microscope stage.
Figure 8: Selecting the slide
"1: Colored Threads Whole Mount" from Cassette #1
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Notice that when a slide is actually on the microscope (or when it is being loaded or unloaded), the
cassette controls are grayed out so you cannot load a second slide until the first is removed. Once the
slide is on the microscope stage, it will be listed in the "Current Slide on Stage" box. The only thing that
the Slide Loader robot can do is return it to the cassette when the "Return Slide to Cassette" button is
selected.
Figure 9: "LOADING SLIDE ... PLEASE WAIT" is displayed
in the "Current Slide on Stage" window
Select the "Microscope" tab to perform the NANSLO lab activity. Once you are finished with the slide,
select the "Slide Loader" tab and select "Return Slide to Cassette" button. Once the slide is returned to
the cassette, the Slide Loader controls are again available to select another slide from the cassette.
ENHANCING THE MICROSCOPE IMAGE
The digital camera mounted on the microscope has a camera control unit that is equipped with a series
of image processing functions that enable you to quickly and easily correct imaging problems that arise
from low or high contrast, poor focus, insufficient or uneven illumination, sample shading or
discoloration and noise. The most common reason for uneven elimination is a light source that does not
completely fill the field of view on lower magnifications. The White Balance should be used only if the
image appears to be brown or gray, and you think you might need to adjust it (although it won't hurt
anything to click this button).
A choice of color modes can be selected in the Microscope Image area and are used to display the image
in different color palettes in order to highlight certain features. The default setting is "Normal."
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Figure 10: Microscope Image Special Effects and Other Image Controls for Camera
Here is a description of each option:
1. In the “Normal” mode, the sample is displayed in its true colors.
2. In the “Negative” mode, the sample is displayed in a color-inverted form, where red, green, and
blue values are converted into their complementary colors. The technique is useful in situations
when color inversion can be of benefit in exposing subtle details or in quantitative analysis of
samples.
3. In the “Blue Black” mode, the black portions of a grayscale negative sample are displayed in
blue. This mode is often useful to reveal details in samples having a high degree of contrast. The
“Blue Black” filter can aid you in examining a wide spectrum of difficult samples.
4. In the “Black & White” mode, a grayscale image of the sample is displayed.
5. In the “Sepia” mode, a brown scale (black and white) image of the sample is displayed. Although
typically this filter is of little utility, it can be employed to alter image color characteristics to
improve the visualization of sample detail.
6. At times, the sample may have an unacceptable color quality. Use “White Balance” calibration
to remove the color cast. This process is often referred to as white balancing.
7. Auto Exposure is on automatically. You do not need to do anything with Auto Exposure unless
you are adjusting the luminance. If you are doing so, you should turn off Auto Exposure by
clicking on the button. The green light is now off. Now adjust the luminance. See explanation
below.
Reference: http://www.microscopyu.com/articles/digitalimaging/dn100/correctingimages.html
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Auto Exposure is normally turned on, but you can turn it off if you want to play around with the
brightness of the light source and not have the microscope camera automatically adjust it. It is usually
best, though, to leave it turned on.
When you turn off the Auto Exposure, the button turns dark green. Some new controls appear that let
you turn the LED off or on, and also adjust the intensity of the light source. The intensity of the light
source can be increased or decreased manually with the dial that now appears next to the Objective
control when Auto Exposure is turned off.
Figure 11: Additional controls available when Auto Exposure is turned off
CAPTURING AND SAVING A MICROSCOPE IMAGE
When the “Capture Image” button is pressed, a high-resolution image of what is currently in the field of
view of the objective is captured. While the image is being captured, the button will be illuminated
bright green. The capture is complete when the light turns off. Be patient as this may take several
seconds to complete.
After the Capture Image light turns off, select the “View Captured Image” tab on the bottom of this
control panel to view the image.
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Figure 12: Click the capture image button (#1), wait till the green light goes off,
and then select the View Captured Image tab (#2)
After opening this image through the View Captured Image tab, you will need to take a snapshot of it
and save it to your computer. There are several ways to do this, depending on your operating system.
WINDOWS:
1.
Pressing the two keys ALT and Print Screen simultaneously will copy the active window into
your computer clipboard. Then you can past it into a document.
2. Windows 7 and above has a Snipping Tool program under Programs/Accessories which can
capture selected areas of the screen.
3. Right click on it and select "Copy" from the menu presented. After right clicking and selecting
Copy, just open a document and right click and select Paste. You can either paste it directly into
your lab report document or into another one for safe keeping until you use it later. You can
use drawing tools in your word processing editor to annotate this image so you can show your
instructor that you know what you were suppose to be looking for!
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Figure 13: Right click and select Copy to paste the image into a document.
MAC:
1. Press these three keys simultaneously –
. This will change your cursor icon into a
little cross.
2. Now press the spacebar, and the icon becomes a camera. Click in the image window you want
to take a snapshot of, and it will save the image to a file on your desktop.
There are lots of free screenshot utilities you can also use to capture this image.
If you are familiar with saving a document to your computer, you also can select “Save Image As” from
the pop-up menu, give the image a name and then select a location on your computer where you want
this image to be saved for future use.
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MICROSCOPE IMAGE VIEW WINDOW
The Image View Window displays the real-time video feed from the digital camera “looking through” the
microscope.
Figure 14: Image View Window
PICTURE-IN-PICTURE CONTROLS - CAMERA PRESET POSITIONS AND PAN-TILT-ZOOM CONTROLS
When you click on the "Picture-in-Picture" button, it turns bright green. A second real-time video feed
from another digital camera appears in the Image View Window. The controls shown in Figure 15 are all
operational when the Picture-in-Picture feature is selected.
Figure 15: Picture-in-Picture Image Controls
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CAMERA PRESETS
There are six camera preset positions.
Figure 16: Picture-in-picture Camera Preset 1 and 6
- Displays the microscope, microscope camera, and a
camera control unit projecting the sample on the
Stage.
Figure 17: Picture-in-picture Camera Preset 2:
Displays a close-up of the objective lens.
Figure 18: Picture-in-picture Camera Preset 3 Displays a close-up of the camera control unit
projecting the sample on the Stage.
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Figure 19: Picture-in-picture Camera Preset 4 Displays the microscope eye piece and
the camera mounted to the microscope.
Figure 20: Picture-in-picture Camera Preset 5 Displays the Condenser Lens underneath the Stage
that focuses the light on the sample. The
Condenser Lens controls the width of the beam. In
some instances you will want a tighter beam while
in other cases you will want a broader beam to
control the image quality. This setting has been
optimized for you.
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PAN, TILT, ZOOM CONTROLS FOR PICTURE-IN-PICTURE
For each camera preset view, additional camera options are available.
1. Use the up and down arrows to tilt the camera up or down.
2. Use the right and left arrows to pan right or left.
3. Use the left "Zoom OUT" arrow and right "Zoom IN" arrow to zoom out and in.
Figure 21: Picture-in-picture Camera - Example of "Zoom In" capability
For more information about NANSLO, visit www.wiche.edu/nanslo.
All material produced subject to:
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