Lab: Microorganisms in the School Environment

How clean is your school??

We have just completed some bacteria labs in our Biology 1 classes.  The first lab we did is called "Microorganisms in the School Environment".  The students really like this one.  Each student is given a sterile Petri dish of nutrient agar and allowed to choose a location in the school.  The purpose of the activity is to determine where in the school the most bacteria are found.  Students take a sterile swab and rub along surfaces in their location, then streak their swab across the surface of their agar.  Dishes are incubated for 48 hours, and the total number of colonies are counted.  


Students are often amazed at the results.  The students are always convinced that the cafeteria and the bathrooms will be overrun with bacteria, but the results usually show that these locations have the fewest bacteria.  Almost always, we find that a locker has the highest number of bacteria!

I don't place a lot of validity on the test results, but it is a fun activity to do when teaching a unit on microorganisms.   Just remember to have the students seal their dishes with tape, and do not allow the dishes to be opened after the bacterial colonies have grown.


Here is the link to my lab on TeachersPayTeachers.com as well as links to some related products.


Lab:  Microorganisms in the School 
Environment

Viruses and Bacteria Complete Unit Plan

Bacteria Homework / Study Guide

Happy Teaching!!

AP Biology Exam: It's Never Too Early to Start Reviewing

Click picture to download PowerPoint.

The key to success is REVIEWING!!

If you have taught AP (Advanced Placement) Biology, then you know that the amount of material that must be covered before the exam is daunting.  I have had great success with my AP exam scores.  I normally have between 60 to 80 students take the exam each year.  For the 2011 exam, I had 65 students sit for the exam, and we had an average score of 4.3.  Admittedly, this is one of the best years I have ever had.  It was a great group of students who were highly motivated.

I am convinced that the key to success is how you review the material with your students.  I begin to review with my students on February 1.  I am fortunate to have a 70 minute class each day.  I give a prayer of thanks for this each and every day, and I realize that most AP teachers do not have this luxury.  Beginning on February 1, I use the first 10 to 15 minutes of class to review a topic that we have previously covered earlier in the school year.  The remaining class time is used to cover new material.  The day before the AP exam in May, I am still reviewing and still covering new material!!

We have to convince our students that they must review, review, review before the exam.  I have written a set of powerpoints that I use for review. These are not teaching powerpoints.  These are just slide after slide of question and answer.  The students are not going to remember every little detail, so I try to make sure that they are solid on the basic facts.

Here is one of my review PowerPoints that I hope you will download.  It covers the characteristics of carbon and the organic compounds.

AP Review: Carbon and Organic Compounds ---- It's FREE!!  I hope you find this useful for your classroom.

Happy Teaching!

Paper Chromatography Explained: Diagram, Lab Ideas, and Classroom Tips

Looking for a low-prep, high-impact paper chromatography experiment to spark curiosity in your middle or high school science classroom? Paper chromatography is a classic lab technique that allows students to separate and analyze mixtures through hands-on investigation. In this paper chromatography experiment, students observe how different substances move along chromatography paper at different rates, and a simple diagram helps illustrate how solubility, polarity, and molecular properties affect separation. Whether you are introducing the scientific method, studying photosynthesis, or exploring real-world applications of chemistry and biology, paper chromatography is a versatile and visually rewarding lab to include in your curriculum.

What Is Paper Chromatography?

Paper chromatography is a simple chromatography technique used to separate the components of a mixture. This method works by taking advantage of differences in solubility and molecular interactions, allowing substances to be identified based on how far they travel up a strip of paper in the presence of a solvent. In the real world, chromatography is an essential analytical tool used in fields such as forensics, toxicology, and pharmacology. Police labs use chromatography to detect drugs and toxins in blood and urine samples, making this paper chromatography lab a meaningful way to connect classroom science to real-world STEM careers.

If you are looking for a ready-to-use paper chromatography lab for your classroom, you can find the complete student instructions, data tables, and teacher notes in my Paper Chromatography Lab resource on Teachers Pay Teachers.

Paper Chromatography Diagrams

These paper chromatography diagrams show how a solvent moves up the chromatography paper, carrying dissolved substances with it. Different components of the mixture travel at different rates based on their solubility and attraction to the paper, resulting in visible separation. This visual helps students better understand how paper chromatography works during the experiment. 

Paper Chromatography Experiment Overview

👉 The process is straightforward but packed with learning potential. A small dot or line of a sample (like ink or plant pigment) is placed near the bottom of a strip of chromatography paper. This strip is then placed vertically into a container with a shallow layer of solvent. As the solvent travels up the paper by capillary action, it carries the components of the mixture with it.

Here’s why the mixture separates:

• Solubility: More soluble substances dissolve better in the solvent and move farther up the paper.
• Molecular Weight: Smaller molecules tend to move more quickly than larger ones.
• Polarity: The cellulose in the paper is polar. More polar substances stick to the paper and don’t travel as far, while non-polar substances move more freely.

Chromatography Lab Ideas for the Biology or Physical Science Classroom

💧 Ink Separation

A fun and accessible introduction to chromatography is separating black ink from markers. Many black inks are actually mixtures of several colors. When placed in water, water-soluble inks spread apart into bands of dye. Not all markers will work the same way. Permanent inks may require rubbing alcohol or another solvent to separate. This gives students the opportunity to test variables and compare results across different solvents and ink types.

🍃 Plant Pigment Separation

This is a favorite in high school biology, especially during units on photosynthesis or plant biology. Students can extract pigments from leaves and discover that the color they see is actually a mix of chlorophyll-a, chlorophyll-b, xanthophyll, and carotene.

Fall is a perfect time to collect a variety of leaves from trees around your school. But if you’re teaching in winter, spinach leaves from the grocery store work just as well.

Materials for a Paper Chromatography Experiment

You don’t need a fancy setup to get started. Here's a basic chromatography kit:

• Chromatography paper (filter paper or coffee filters can work in a pinch)
• Small containers (test tubes, jars, or beakers)
• Solvents (water, rubbing alcohol, acetone, or other safe household solvents)
• Samples to test (leaves, markers, food dyes, etc.)
• Pencils, rulers, and scissors

Tip for teachers: Always test your materials and solvents in advance. Be sure to follow proper lab safety protocols, especially if using alcohols or other flammable substances.

Paper Chromatography Lab for High School Biology and Chemistry

Paper chromatography is one of the most effective chromatography labs for high school biology and chemistry classes because it allows students to visualize molecular differences directly. This chromatography experiment helps students understand key concepts such as polarity, solubility, intermolecular forces, and molecular structure.

In high school biology, paper chromatography is commonly used to separate plant pigments during photosynthesis labs. In chemistry classes, students use chromatography to analyze ink, food dyes, and other mixtures. Because the setup is simple and inexpensive, this chromatography lab is ideal for introducing experimental design, controlled variables, and data analysis.

This paper chromatography lab also helps students connect abstract molecular concepts to real, visible results, making it one of the most memorable chromatography activities in the science classroom.

What Solvent Should You Use?

The answer depends on the solubility of your sample. Water works well for many inks and food dyes. For permanent markers or plant pigments, isopropyl alcohol or acetone may be more effective.

Pro Tip: Encourage students to design their own investigations. They can test multiple solvents on the same type of ink or compare different brands of markers to determine which separates most clearly.

Why Use Paper Chromatography in the Biology Lab?

Paper chromatography gives students hands-on experience with:

• Designing and conducting controlled experiments
• Observing molecular behavior and physical properties
• Making qualitative and quantitative observations
• Connecting lab techniques to real-world applications

It’s also a visually exciting lab. Watching vivid colors separate into bands on a strip of paper never gets old, and makes for excellent lab notebook sketches!

Check out this post on my blog, Leaf Pigment Chromatography, for additional photos and information. 

You may also be interested in my osmosis lab using dialysis tubing and my potato osmosis experiment, which help students understand diffusion, osmosis, and molecular transport in cells. Check out these blog posts:

• Potato Osmosis Experiment
• Osmosis Lab Using Dialysis Tubing

Frequently Asked Questions About Paper Chromatography

What is chromatography used for?
Chromatography is used to separate and analyze mixtures by observing how different substances move through a medium. Scientists use chromatography in fields such as forensics, medicine, environmental science, and food testing.

Why does paper chromatography work?
Paper chromatography works because different substances have different attractions to the paper and the solvent. These differences cause components of a mixture to travel at different speeds, resulting in separation.

What can students learn from a paper chromatography experiment?
Students learn key lab skills such as experimental design, data collection, observation, and analysis while exploring concepts like solubility, polarity, and molecular interactions.

How do you perform a paper chromatography lab in the classroom?

To perform a paper chromatography lab, students place a small sample of ink or plant pigment near the bottom of chromatography paper and suspend the paper in a solvent. As the solvent travels upward, it separates the mixture into its components based on solubility and polarity. Students can measure how far each component travels and calculate Rf values to analyze the results and compare substances.

This targets extremely valuable keywords:

• paper chromatography lab procedure

• how to do paper chromatography lab

• chromatography lab classroom

Ready to Try This With Your Students?

These chromatography labs have been classroom tested and include complete student instructions, answer keys, and teacher guidance for easy implementation. If you're looking for classroom-ready chromatography labs, I have two student-tested resources that include everything you need: detailed procedures, printable lab handouts, answer keys, and grading rubrics.

🔬 Matter Lab Stations: Ink Separation – Perfect for introducing lab skills and the scientific method in both middle and high school.

🌿 Plant Pigment Chromatography Lab – Ideal for exploring photosynthesis and leaf pigments in your high school biology class.

Both labs are designed to save you prep time while providing meaningful, standards-based instruction. You can find them in my Teachers Pay Teachers store.

 

 

Excellent resources for teaching tips, strategies, and lessons.

If you are looking for anything teacher-related, you are sure to find it at one of these sites!

I hope that you are already aware of these wonderful sites for teachers. They are not strictly science related. Rather, they offer a wide range of materials for all ages and all subject areas.

Are you looking for:

• Lesson Plans?
• Teaching strategies?
• Printables?
• New ideas for presenting basic skills?
• Fun activities?
• Creative educational crafts?

Whatever you might be looking for in your teaching or for your classroom, I feel confident that it can be found through one of these sites.

The Lesson Cloud

This blog is a collaborative blog written by almost 100 different educators.  The postings represent a great balance of subject areas and age levels.

Classroom Freebies

The header on this blog says it all.... "Top educators bringing you the best resources for your classroom every day and always free!"
It just can't get any better than "FREE"!  From this site you can download almost anything.  Again, the free materials cover all subject areas and all age groups.

Teaching Blog Central

This is your source for all teaching blogs, all day long which are divided up in to specific grade levels just for you!  You will find a different website that has a blog roll which includes blogs that are primarily geared toward that specific grade level, with a few collaborative blogs thrown in for good measure.  Now, you can see blogs and posts that are most relevant to you and they are all in one place!  This allows you to find the teaching blogs you need.  Looking for blogs written by high school teachers?  Simple click on "High School Herd".  There is a blog roll for each subject area.


I hope that you will take some time to look these over.  I guarantee it will be time well spent.

Happy Teaching!!

What Does This Have To Do With Biology?

We went to Disney World!

I have completed deserted my blog for over a week, but now I am back and am looking forward to a great year!  The day after Christmas our family went to Disney World for a week.  Yes, it was crazy crowded, but very magical.  The decorations were so pretty and festive.  We were in the Magic Kingdom on New Year's Eve, and I have never seen so many people in my entire life, but the New Year's Eve fireworks were out of this world!!

Now for a reality check.  School is starting back.  Time to grow up and be a responsible teacher/mom/wife again.  I have been racking my brain trying to think of something "biology related" to write about.  I have some ideas for new labs and activities for my classes this semester.  As I try them out on my students, I'll pass them along to you.

For now, I have some wonderful photos to share with you.  One of our days at Disney was spent at the Animal Kingdom Park.  We arrived at opening which was 7 am for the holiday crowds.  It was a cool morning, but very sunny.  We headed straight for the Kilimanjaro Safari ride. Because of the early time, and the coolness of the early morning, and because it was feeding time, we had some amazing encounters with the animals.  Here are some photos for you.

This giraffe walked right up to our truck
and practically stuck his head inside!

Beautiful ostrich!

The rhino was heading toward the feeding station
and walked within 10 feet of our bus.

Is there anything any cuter than a baby elephant??

I don't know why, but I just love flamingos. 

I hope that you all had a wonderful holiday season and a very Happy New Year. Here's to a great 2012 with our families and our students. My blog has survived the first year, and I greatly appreciate the support from all of you.  

Happy Teaching!!

Excellent Resources for Teaching the Protists

Excellent Short Videos of Protists

Just as my school was getting out for the Christmas break, I was finishing up a unit on the Protists with my biology classes.  I am very fortunate to have the use of an extremely well equipped high school lab, but before I took my students to the lab to complete my protist lab, I wanted some short video clips to use in the classroom during my lecture.  Most sites that host video are blocked at my school, but I was very pleasantly surprised to find several sites that I could access and use in my classroom.

Here are a few of the sites that I found.  What I liked the best was the short length of each clip.  With each of these sites, I could show 20-30 seconds of one organism and then move on to another organism.

Each of the sites listed below are free and the quality of the video is excellent.

Nikon Microscopy:  This was my favorite site.  Not only did it have the clips of the protists I was looking for, but it also has video clips of annelids, cnidarians, crustaceans, etc.  I'll be going back and using this site again and again.

Fun Science Gallery:  This site has 38 movies of bacteria, protists and freshwater multicellular organisms.  This site gives a few short sentences on particular structures to watch for as the video plays.

Natural History Museum Microbiology Video Collection:  All I can say about this site is just "Wow!!"  If you can't find what you are looking for here, it probably doesn't exist!

After teaching the about the protists in my classroom, I took my students to the lab for my 3-day lab on the protists.  Having used the short video clips in the classroom made my lab run smooth and easy.  I have already written a blog post about this lab.
You can access it and read about it here:   The Living Protists Lab

Happy Holidays and Happy Teaching!

Scientific American "Citizen Science" - A Fantastic Resource

Turn your students into scientists!

Your students can actually help collect data for actual scientific research projects!

Hardly a day goes by that I don't check the Scientific American web site.  Not only does it have great news stories for me to share in my classroom, but it has a section called "Citizen Science" that is just a fantastic way for us science teachers to involve our students in actual, ongoing scientific research projects.  This explanation comes directly from the Citizen Science section of the web site:

Currently, there are two projects available that particularly interest me.  Both of these can be done with students at school, or can be done by children with their parents at home during the holidays.

This project is called "Christmas Bird Count".  "The National Audubon Society's Christmas Bird Count(CBC) is an early-winter bird census, where thousands of citizen scientists across the US, Canada and many countries in the Western Hemisphere, go out over a 24 hour period to count birds.

Count volunteers follow specified routes through a designated 24-kilometer diameter circle, counting every bird they see or hear all day. All CBC’s are conducted in the period from December 14 to January 5 each season, and each count is conducted in one calendar day.
The data collected by observers over the past century allow researchers, conservation biologists and other interested individuals to study the long-term health and status of bird populations across North America. When combined with other surveys such as the Breeding Bird Survey, it provides a picture of how the continent's bird populations have changed in time and space over the past hundred years."

You have to sign up for this project through the link above to find out if this is being done in your area.  You will be assigned a specific route to follow.  

This project is called "The Whale Song Project - Whale FM".  

I particularly like this project because it can be done in the classroom or at home on your computer.

"Through the Whale Song Project, citizen scientists are presented with a whale call and shown where it was recorded on a map of the world’s oceans and seas. After listening to the whale call citizen scientists are asked to listen to a number of potential matching calls from the project’s database. If a match is found, the citizen scientist clicks on that sound’s spectrogram and the results are stored.
The dataset generated by this project should help scientists to answer a number of questions regarding whale communication."


There are new projects being added to Citizen Science all the time.  This is a fantastic opportunity for the students in our science classrooms to participate in current scientific research projects.

Happy Teaching!!

P.S.  I am adding this little tidbit of information.  After my blog post was published, I was made aware of this site:  SciStarter.  It has a wealth of information on projects that you can join.