Points to think about and discuss while writing your lab summary: 1. How do the
ID: 212446 • Letter: P
Question
Points to think about and discuss while writing your lab summary: 1. How do the antigen-antibody interactions produce an observable color change? 2. Does the color intensity correlate to the concentrations you calculated for samples 1 12? 3. How would you expect the colors to be different for the following samples: 10ul beer, a crushed up Whopper candy, and a 10ul Gerber's strained peas? 4. Why is it necessary for an enzyme to be linked to the secondary antibody? 5. Is it possible to be a "little bit allergic to gluten? 6. Are the foods labeled "gluten free" correctly labeled based on the FDA guidelines? 7. OraQuick, the first at home HIV test, was introduced to the marketplace in October 2012. In regard to this laboratory experiment, please explain in your own words, thoroughly, how this test would work to confirm whether or not you have the HIV virus in your body or not? Is this an example of a direct or indirect ELISA? How do you know?Explanation / Answer
1. Antibodies are utilized to determine the presence of an antigen (Ag). Normally the antibodies (Ab) are conjugated with enzymes. So when the enzyme-linked Ab binds to an Ag, a substrate is added on which the enzyme acts and produces a color.
2. Not enough information is present to answer this question.
3. Not enough information is present to answer this question.
4. In case of indirect ELISA or sandwich ELISA, we use secondary Ab. The primary Ab binds to the Ag, whereas the secondary Ab is specific to the primary Ab ( in case of indirect ELISA). This increases the magnitude the signal. The secondary Ab is also linked to an enzyme which acts on a particular substrate rendering the color of the Ab-Ag reaction.
5. Gluten is a protein found in grains (barley, wheat etc). Gluten allergy is a misleading term (often confused with wheat allergy) but there is a disease known as the celiac disease which involves diarrhea, rash, abdominal pain after ingesting gluten containing food items.
6. When you see the words "gluten-free", on an FDA-regulated food, it indicates that the it is either:
OR
AND
It is a common misconception that foods labeled "gluten-free" can or do contain zero parts per million (ppm) of gluten. At this time, no validated tests are able to accurately detect gluten at zero.
7. Oraquick detects the Ab for the HIV. After oral fluid collection by swab if only one line formed the test is negative and if two lines were formed it was positive for HIV in 20-40 minutes. This is an indirect ELISA as you would require another Ab to give the result.