University lab closed? Learn about ELISA assays with these virtual resources.

In my biotech virtual classes, we learned that ELISA assays use antibodies to detect and quantify proteins, but we didn’t have time to study how an ELISA assay works, nor the steps for completing one. To the internet I went and found more resources than I could need!

Here’s what I did to learn, study and commit to memory ELISA basics.

I combined a video, praxilabs.com simulation, and a few websites to get a reasonable understanding of the principles behind the various ELISA assays and the steps involved to complete them.

It turns out that there are several types of ELISA assays and which one you use depends on factors such as cost, time, and sensitivity-level required. The tests are basically broken down into direct ELISA, indirect ELISA, sandwich ELISA (direct or indirect) and competitive ELISA. The video describes each one as does numerous websites. I used the following:

BIO RAD

Cellsignal.com

Bosterbio.com

The sandwich ELISA simulation by praxilabs.com gives you a real feel for the steps you would be required to do in the real world (except that virtual world time compression makes everything faster!). I ran through it once before watching the video, but it made a whole lot more sense after watching the video and creating this free Quizlet.com flashcard set.

My steps for learning about ELISA assays:

1. Watch the ELISA video made by the Biomedical and Biological Sciences YouTube channel. I recommend taking notes to help you really pay attention to the material.

2. Complete the ELISA Sandwich simulation by Praxilabs.com. If you do not have/want a subscription you can watch the video version on YouTube.

3. Deepen and strengthen your knowledge by using these Quizlet flashcards that I made. Here I combine building assay vocabulary with learning the basic steps of most ELISA assays.

My favorite way to use Quizlet is the multiple choice option – click on “Learn”, then click on “Options”. A window will open – scroll down and uncheck the “flashcards” and “written questions” boxes. Now only “Multiple choice questions” is checked.

Diagram attribution: NickCT, CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons

Learning Biotech in a Pandemic!

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In the fall of 2020 I began coursework in earning a biotechnology certificate from Montgomery College – a top-of-the-line program for which I am very thankful!

Unfortunately the program is 100% virtual right now, which is a tough way to learn laboratory science. My biotech posts are to share how I am supplementing my courses with a variety of online resources to prepare myself for working in a real lab, rather than a virtual one!

  1. Biotech Virtual Learning – Agarose Gel Electrophoresis
  2. Virtual Learning about Protein Electrophoresis (SDS-PAGE)

Check back for new posts!

Biotech Virtual Learning – Agarose Gel Electrophoresis

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Taking lab courses that are only VIRTUAL requires some creativity on the part of the student if you really want to prepare yourself for a job. To review agarose gel electrophoresis, I used a FREE VIRTUAL SIMULATION.

Praxilabs.com simuation guides you through the steps of separating DNA fragments by size via electrophoresis.

You begin with preparing the agarose gel by combining the gel powder with TAE buffer, heating and cooling it, and then adding a dye. I like that the activity includes setting up the electrophoresis device along with having to enter the voltage before running the experiment.

These simulations do have their challenges – absolultely no moving forward until you properly cap the bottles and discard your used pipette tips! Once you figure this out, the simulations run a lot more smoothly.

Once the device is set up, you prep the DNA samples and pipette them into the wells of the gel tray. I got stuck for a bit with the requirement to put a dark object underneath the gel to make it more visible so I had to go to the YouTube video to figure out what to do there.

The simulation ends with you using a UV Transilluminator to see the separated DNA fragments. However, the lab ends rather abruptly with only brief glimpse of the stained fragments. That was disappointing! But otherwise, I highly recommend checking it out for yourself.

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Learning Biotech in a Pandemic!

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Trying to change careers into biotechnology during a pandemic has its challenges – the biggest that my in-person lab courses are completely virtual! I found that it was really necessary for me to supplement my coursework with my own investigations into the basic laboratory techniques that I would otherwise be performing in-person if the college would allow it. I am sharing how I organized my own learning as it may be helpful to others in my situation, so I’m posting the resources I am using for each technique.

Virtual Learning about Protein Electrophoresis (SDS-PAGE)

There are a lot of videos on YouTube that probably do a great job of explaining protein electrophoresis, but I can’t watch them all and so I had to just choose (eeny-meeny-miny-moe style). I ended up using the videos of two sources for most of my lab education: YouTube channel “Biomedical and Biological Sciences” and “Bio-Rad Laboratories”. I find the videos to be well-made, completely on-topic and not too long for my attention span!

Videos:

1. The principle of SDS PAGE-a full and clear explanation of the technique and how does it work – – explains how this type of electrophoresis separates proteins by molecular weight. Explains separating and stacking gels, how to prepare the protein samples with denaturation buffers, the key role of SDS detergent and the other components of the buffer.

2. SDS-PAGE of Fish Muscle by Bio-Rad – shows all the steps for setting up the electrophoresis device and removing the gel and moving it to a staining tray.

Virtual Simulation:

Praxilabs.com – Protein Electrophoresis (Polyacrylamide Gel Electrophoresis – PAGE). This simulation is NOT free, but I purchased a one-month subscription for only $9.99 so I could do 8 different simulations.

Simulation Details: This simulation has me prepare the polyacrylamide separating and stacking gels, load the gels, fill the device with electrophoresis buffer, add loading buffer to each sample and then fill the wells with the protein standard and the four samples.

It begins with prepping the glass plates, and includes using vortex mixers and water baths, along with the electrophoresis tank and power supply.

OPTIONS:  You can see what the simulations are like in two ways: 

1. Video versions of many of their simulations are on YouTube. These are really helpful in case you get stuck on a step. I could not find one for this exact simulation, but there is one for Agarose Gel Electrophoresis.

2. The simulation for this technique is also FREE at praxilabs.com so try it out there too!

Practice with Taxonomy

This Internet Activity, made in Google Docs, introduces students to taxonomy with a focus on animal classification. 

Activities Include:

  • Students practice writing scientific names of species within specific classes of vertebrates in the phylum Chordata (such as mammals and birds) and classes of invertebrates in the phylum Arthopoda (such as insects and arachnids).
  • Students learn about differences between reptiles and amphibians.
  • Students match the phylum to the invertebrate such as crabs and sea stars.

See a preview of the worksheet here.

I’m loving this… Virtual Circuit Builder!

With DISTANCE LEARNING I wasn’t able to do the hands-on electrical circuits lab with my wonderful 8th graders so I had to come up with another way for them to learn the basics. A web search brought me to this really cool VIRTUAL circuit builder that does NOT use Flash – which is awesome because Flash is no longer supported by Chrome.

Here’s a brief video of how this Phet interactive works.

Pros:

  • easy to learn how to use
  • can build series and parallel circuits
  • there are a few different components to experiment with such as the light bulb, resistor and switch
  • can experiment with how adding and subtracting components affects resistance.
  • multiples of all of the components can be added, such as adding two batteries to increase voltage
  • the anmeter is fun to play with!
  • you can view the parts of the circuits in symbols to practice with engineering pictograms

Cons:

  • There are no particular directions so if you want to be sure your students really learn what you want you’ll need to come up directions for them.

Don’t have time to design an activity? No sweat – use mine!

Internet Activity:  Build Circuits Virtually!

My worksheet guides students in
constructing series and parallel
circuits using the Phet interactive.
No prep required – just have
students watch the video above so
they know how to attach/detach
components.

Pond Dip – Bring an Ecosystem into the Classroom

Studying aquatic microorganisms is engaging and very educational.

Here I share how I teach a 7th grade lab on finding protists and microscopic animals in pond water. This may seem daunting if you are not familiar with the organisms or haven’t had the time to organize the activity. I hope that I’ll give you all the information you need for a successful lab.

aquatic beautiful bloom blooming
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Why take the time for this lab? Well, no one is going to be excited about algae by looking at a picture of it. Algae in the macroscopic world is called POND SCUM, but under the microscope it’s BEAUTIFUL.

Also, many standards can be addressed in a pond dip lab:

  • modeling ecosystems and ecosystem interactions
    • food chains, food webs and trophic levels
    • nonliving and living factors within an ecosystem
  • biological diversity
    • taxonomy and evolutionary relationships among species:
      • single-celled protists
        • algae – single-celled organisms with plant-like characteristics
        • protozoans – single-celled organisms with animal-like characteristics
      • microscopic animals – all multicellular
        • crustaceans, aquatic worms and rotifers
  • cells
    • single-celled organisms are microscopic, but have all of the characteristics of living things
    • microscopic multi-celled organisms such as microscopic crustaceans and worms
  • Using dichotomous keys and technical language – meet Common Core standards for using “key terms” and “domain-specific words and phrases” used in a “scientific and technical context”.

green toad in water
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The supplies are simple and usually found in the typical middle school or high school biology classroom. The only things you will need to gather otherwise is the microorganism-rich water and organism keys; I provide you with information on both.

Supply List:

  • microscopes with at least 100x magnification
  • containers (3 or more) to hold the pond water
  • pipettes (3-5 per container)
  • concavity slides (designed to hold a drop of water). Example here.
  • microscope cleaning tissues (such as Kimwipes®)micro key
  • dichotomous keys to aquatic microorganisms
    • Guide to Identification of Fresh Water Microorganisms – this one I print enough copies for each group
    • Pond Life Identification Kit – this source has a lot of links that are useful to the teacher and can be used by students if internet access is possible during the lab
    • Protozoans and Small Animals – this website is also helpful; click on the phylum for more drawings and information – I print the Ciliophora page and multicellular animals page for extra reference materials.

      pond-water.jpg
      Plastic container with pond water. The little leaves on top or the decayed plant matter on the bottom are the best places to find microorganisms.
  • pond water – this might be the one supply that keeps teachers from doing this lab. Micro-rich water is not too hard to find in most places – any relatively natural fresh water source will do, such as ponds, streams and lakes. Artificial ponds such as a Koi ponds work too. Even well-established fish tanks have a micro-community within them!
    • How much water? I collect about one gallon (or less). Make sure the water has some debris in it – the debris provides food and hiding places for microorganisms. Most are found within the debris (dead plant matter and silt).

Warning:  Do NOT add tap or bottled water to your pond water. Drinking water usually has some chlorine in it – this will kill your organisms! If I need additional water for rinsing slides I use water that is treated with water conditioner for fish tanks. The conditioner removes chlorine.

Preparing Students for this Lab

I have my students do this lab after we have studied the basic characteristics of the 6 kingdoms of life. In this lab we can study the protist kingdom as well as microscopic animals. Since we always are lucky to see crustaceans, worms and rotifers (amazing little animals!), my students are able to observe the differences between the animals and the single-celled protists.

The key, I think, is that your students should become a little familiar with the organisms before beginning. I show some videos on actual pond water organisms (always creates excitement for the lab) in addition to some other videos about the protist kingdom.

flagella/cilia video                        microscopic life video (shows many types)

pond life video (fast forward past the tadpole to learn about protists)

Daphnia video (microscopic crustacean)           rotifer video

pond dipAdditionally, I review the possible types of microscopic animals we hope to find. Lastly, my students complete my Virtual Pond Dip WebQuest a few days before.

Showing Students What To Do

First, students will need to know how to use the microscopes. With the concavity slides, my students are able to use the low magnification (100x), but not the high because the lens would go into the water.

Second, model how to make the slide, use the slide to find organisms and clean up the slide.

  • Model making the slide – show how the ONE drop of water goes into the depression within the slide. Show how to put a cover on the slide if you are using them.
    • Model using the pipette to get a sample from the “dirty” bottom of the container. Most organisms will be among the debris, not in the more clear water.
  • Model carefully carrying the slide to the microscope and carefully placing it on the stage.
  • Model how the student will need to move the slide and change the focus routinely to find the organisms. The water drop is 3D so changing the focus is required to see through different levels of the drop.

Third, explain that if what they see is not green and/or not moving it is not alive. Students naturally want every little thing they see to be an amoeba or hydra or leech! I give a clear direction – don’t call me over to verify that you are looking at sand particles or dead plant matter. If it isn’t moving or green, then just keep on looking.

Fourth, Model how to return the water drop to the container (I prefer to preserve my organisms for others to see as much as possible). I demonstrate that the drop should be poured into the container and then the slide should be gently tapped on the side of the plastic container to save as much of the water as possible. Another option is to rinse the drop into the container using a small squirt of conditioned tap water. Afterwards, dry the slide with a tissue before adding a new drop.

Fifth, Verification. All identifications have to be verified by me. However, students must tell me what they think they are seeing before I will check the microscope. Otherwise, students will use me as their ID key rather than the actual keys.

Assessment

This Google Doc provides the information for my required documentation for 7th graders. Students must find 6 different organsims that meet the criteria. The 2nd page has the circles for their drawings. I recommend that students use only pencils and colored pencils.

Lab Performance Rubric. With trial and error (lots of error) I found that providing a lab performance grade keeps my students on task and following the lab rules. You might find this editable rubric handy.

If I had more time and if I were teaching this to high school I would add more criteria for the assessment. Ideas are for students to have to use information from the organism keys to justify their identification. Another would be to construct a food chain/web of the types of organisms found.

Please share your experiences or ideas with pond dips in the comments section below.

 

Earth Science

 
two person walking on unpaved road
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All Webquests Include a Google Doc Version – Excellent for Distance Learning!

The Rock Cycle – A Webquest
Plate Tectonics (Tectonic Plate Theory) – a Webquest
Earth’s Interior Structure (Core, Mantle and Crust) – A Webquest
Active Volcanoes! In the Ring of Fire – A Webquest
Volcanoes! Of the United States – A Webquest
Webquest Bundle: Plate Tectonics, Ring of Fire & U.S. Active Volcanoes