Complement Fixation Test

There are three diagnostic methods used to identify viruses; the direct, the indirect and serological techniques. Complement fixation test is one of the serological tests used in virology to identify the presence of specific antibodies or antigens. In this context, complements are proteins in series form within the patient's serum which act in response to an antibody antigen complex. In case the reaction takes place on a membrane, pores are produced causing damage to the cell.

Requirements:
• Commercially produced complements from guinea pig
• Patient's serum
• Red blood cells preferably from sheep

Procedure:
1. In complement fixation test, venous blood is collected from the patient and serum isolated.

2. It is natural for individuals to differ in the quantity of complement in serum. With the purpose of eliminating any negative effects these complements might have on the test results, the serum complements are substituted with standardized complement proteins. The complements are destroyed through heating, but care is taken to preserve the antibodies. This can be achieved because complements are vulnerable to heat than antibodies. Thereafter, the standard complements area added into the serum.

3. Into the serum, the antigens of concern are added and the preparation incubated.

4. Red blood cells are added into the preparation

Results:
In complement fixation test, incubation is necessary as it gives complements a period to fix itself onto antibody antigen complex, that is, if it is present. If this happens, complements will not be available to act on the red blood cells and cause hemolysis. As a result, a positive test is designated by the presence of the red blood cells. The cells are observed at the bottom of the beaker. On the contrary, a negative complement fixation test is indicated by the lysis of the red blood cells. The red color of hemoglobin is observed as it spreads in the beaker due to lysis.

Testing for antigens:
It is a common practice in serology to test for antibodies in complement fixation test. Nevertheless, it is feasible to test for antigens. In this case, the test serum is supplemented with antibodies which must be specific in nature. This induces the formation of complement.

Advantages and disadvantages:
The test is cheap as it does not call for expensive equipments and reagents. Again, a large number of viral infections can be screened using complement fixation test. However, it should be noted that the test is labor intensive and frequently non specific.

What Is Cholesterol, Really?

No doubt you have heard that high cholesterol is bad for you and can cause all sorts of health complications, but do you know what that really means? Do you know what is cholesterol?

Is it really bad?

Actually no, not all cholesterol is bad. In fact, you have to have it in order for your body to function properly. Cholesterol helps your body to create cell membranes, absorb vitamin D, create bile, and it will offer itself up for the creation of hormones. Not too shabby.

The problem is that there can be too much of a good thing. High cholesterol levels can lead to serious health complications. Some of these problems are things like; high blood pressure, strokes, heart disease, and all of these medical issues can lead to death!

The two types

What's confusing in the answer to the question of what is cholesterol is that there are actually two types of cholesterol, but they get lumped together. There is a lot of boring, medical jargon that explains what the differences are between the "good" and "bad" kinds of cholesterol, but let's try and keep it simple.

So what is cholesterol? Well, cholesterol's official medical name is a lipid. Lipids are things like waxes, oils, and fats and can't dissolve in your body. They also can't move around on their own, so they have to hook-up with a protein and this duo transforms into a lipoprotein. But the combination happens in two different ways, hence the two types of cholesterol.

HDL and LDL

If there is more protein than lipid it is considered a high-density lipoprotein, or HDL. This is the good type of cholesterol. But if there is more lipid than protein you have the bad type of cholesterol known as low-density lipoprotein, or LDL.

The LDL's are slow moving, and tend to clump together in your arteries. This is when they cause complications like heart attacks. They block the blood flow. The HDL's on the other hand move fast and don't get side tracked by other bits of cholesterol that are hanging around in your blood stream. HDL's are so good that they do more than just avoid causing problems. They will actually absorb any LDL's they come across; which helps your body prevent blockages and other medical issues.

Cholesterol awareness

If your cholesterol is high you probably won't know it. In fact, you could do all the right things to stay healthy and still have high cholesterol. A lot of cholesterol problems stem from genetics. What this means is you need to have your cholesterol levels checked every year as part of your annual medical checkup. And like it or not, this testing should start in your early twenties.

When you get your blood tested you will want and overall score of less than 200. A doctor will be able to tell you the breakdown between the HDL and LDL levels in that score. The general rule of thumb is your LDL to HDL should be a 3-to-1 ratio. For the LDL levels you will want to be between 100 and 130 and HDL the average is 55, but higher is better.

There are many things that you can do to keep your cholesterol levels healthy. Eating right, getting exercise, and getting regular testing will help your chances of healthy cholesterol and awareness. If you are fighting genetics then you might have to follow a stricter regimen to help keep your body healthy.

That is the basics of what is cholesterol.