Difference between Positive and Negative Control | Positive vs. Negative Control

Positive vs. Negative Control

Difference between Positive and Negative Control: – Medical and scientific results or experiments are always and done under a controlled environment. There are some rules and regulations under which this entire process gets completed. Sometime we use the terms positive and negative control. What is meant by the positive and negative control and especially what is the difference between positive and negative control?

Difference between Positive and Negative Control

Negative and positive controls are usually described as the parameters of the experiment. A positive control is an experimental treatment which leads to the desired results just as the researcher expects. The negative control is an experimental treatment which does not lead to the expected results. Thus, the primary difference between positive and negative controls lies in their result producing capabilities in the experiment.

  • Positive Control

A positive control is an experimental control which gives the positive results (the results that lie within the expectations of the researcher). Researcher uses the controls to test the respective variations caused in the results by changing the value of these controlling factors. A positive control is a useful proof to show that the system, reactants, and the environment, under which the experiment is taking place, are functioning without any errors. This means, if a hit and trial method are used, the positive control will not likely produce the accurate results. Therefore, by making use of such controlling factors, a researcher can identify and optimize the procedure without wasting time, effort and money.

For example, when testing a plant extract for its anti-bacterial properties, in antimicrobial substance experiment, a known anti-bacterial compound is employed as a positive control. It produces a dominant bacterial growth inhibition area inside which the test needs to be held. So, if one observes a prominent growth inhibited zone even inside the area surrounded by the positive control, it would prove that the experimental setup is working well without errors.

  • Negative Control

Negative control usually produces no response in the experiment. In experiments, negative control should be designed in a way so that it does not produce the desired outcome of the experiment. In the case of the example given above, let’s say that the experiment is taking place on a disk-shaped structure. So, to introduce a negative control in the system, the disk is soaked with sterile unadulterated water. In sterile unadulterated water, there is no antimicrobial compound. Hence, bacteria can grow without being inhibited. In case, that an inhibition is discovered in the negative control, it indicates that something is wrong with the experiment.

Major Differences between Both Positive and Negative Control

  • A positive control is an experimental treatment which is performed with a known factor to find the desired impact of the treatment.
  • A negative control is a trial and error treatment which does not cause the desired result of the experiment.
  • Both the positive and the negative controls are an important part of any experiment system.
  • Both of the controlling factors are usually used to improve the reliability of the experimental system.

So after reading these major differences between positive and negative control, now the concepts of difference between both should be clear in your mind. Keep visiting the website to learn more about such specific terms that confuses you.