Featured Lab for Fall 2015

HIV Testing

The Enzyme linked Immunosorbant Assay is a corner stone of the early disease diagnosis and monitoring. Its importance stems from its high degree of specificity, relative ease of use, and low cost. This activity was originally written by Cornell University biochemist Jim Blankenship during the early years of the HIV/AIDS epidemic. Before effective treatments were available the HIV ELISA was a crucial public health tool to identify infected individuals. Since that time the ELISA has been used to test for Hepatitis C, Helicobacter pylori (ulcer causing bacterium), SARS, Ebola, and almost any other emergent infectious disease crisis. The wide use of this test associated with disease outbreaks covered on the nightly news provides an excellent opportunity for teachers capitalize on students current interests to instruct them about important concepts in biology.

Relevant Concepts

Biology of antibodies in fighting disease. Antibody diversity/specificity/memory.

Protein structure and function.

Public health and disease surveillance.

Forensics.

Resources available for this lab:

HIV Testing lab activity.

ELISA Kit $46.95 Kit contains all reagents and equipment required for 12 students or student groups to complete the activity.

The World Wide Web isawash in resources students can use to expand or enhance their study of this medical testing procedure and the many disease for which it is used as a primary diagnostic tool.

Previously Featured Labs

Golden Rod Gall Size as a Result of Natural Selection

The goldenrod gall lab is a fun companion activity to compliment instruction in several areas of ecology. The activity requires sharp observational and reasoning skills to identify the various organisms found in the mature goldenrod gall. Students will learn the life cycle stages of several insect species and discover a complex system of host/paratsite/predator relations. Advanced students can make detailed measurements of gall size and analyze the relationship between size and species graphically and using statistical methods.

Resources available for this lab:

Get the gall lab activity. This link will take you to the page where you can download the lab and learn other important information concerning the use of the lab and supplies needed. 

Read a student lab report of this activity. This report was provided by George Wolfe, Director, Dominion High School Academy of Science, Sterling, Va. View it here.

View a slideshow of the gall and its denizens. Twenty four slides depict the common organisms found in this goldenrod-gall fly system. View it here.

 

 

View West Hill Bio's Golden Rod Gall product.

Collecting galls:

Galls can be collected from fall through late winter. In fall, the characteristic golden-yellow flower2 of the goldenrod make the fields easy to spot. Galls form below the flowery crown of the plant, so it is necessary train your gaze below the top of the plant to find them. Galls will be present on a minority of plants but with a little experience it will become easy to spot them. In my experience plants bearing galls are often found in clusters so if a gall is found on one plant look carefully for others to be found on plants nearby.

By the time school starts in the fall, the galls will be mature and the various species of parasite will be present. Gall flies do not pupate until Spring and so gall fly pupae will not be present in galls collected in the fall. Galls collected in fall and stored under ambient conditions will continue to mature. I once opened a gall left over the winter and found a pupal case that when opened produced a live fly that crawled out onto my thumb. Depending on weather conditions birds will begin to prey on gall fly larvae by mid winter. During a cold, snowy winter it can be a challenge to find galls that the chickadees haven't raided.

Remember that when collecting specimens to leave some behind to produce galls for the next season, for birds to eat, and to fulfill other ecological functions of the goldenrod-gall fly system.

 

Nanotechnology: molecular imaging

Atomic force microscopy is an advanced type of scanning electron microscopy with a resolution capable of imaging the surface of molecules. The methodology involves rastering a probe over the surface and recording deflections with a laser on a screen of photodiodes. This activity involves the use of a black box containing a structure of unknown shape and a probe that can be used to detect the surface of the object. Students record the position of the surface by directing a laser pointer at a screen. By assembling a sieries of such screens the students are challenged to reconstruct the object in the box.

Bathymetry? From the ultra tiny to the globally large, the basic principle of mapping surfaces is similar. Here's a link to a novel application using the Laser Guided Topographic Imaging Module to map the unknown reaches of the Earth's oceans provided by George Wolfe.

Bathymetry Module

 Need to know more about Atomic force Microscopy?

Flash tutorial from Beckman Institute for Advanced Science and Technology
University of Illinois at Urbana-Champaign.

Animation from Australian Goverment's National Measurement Institute.

Resources available for this lab.

Get the AFM lab activity. This link will take you to the page where you can download the lab and learn other important information concerning the use of the lab.

View West Hill Bio's AFM kit, the Laser Guided Topographic Imaging Module provides all of the materials needed to for one student group to perform this activity.