30/05/2020
HERE IS WHY MICROSCOPES ARE NOT USED IN TESTING COVID-19
You must have seen the spiked balls that have been flashed on your television. The television industry has created a mental picture of corona virus that can be very misleading. In the pictures doing rounds on all television channels, the corona virus is potrayed as large balls with numerous spikes on their surfaces. The corona virus ‘balls’ appear larger than red blood cells in the images. This is absolutely misleading.
In general, viruses are known to be very minute when compared to human red blood cells. In fact, the largest known viruses known as pandora viruses are about 0.2microns (micrometers). An object of such a size can hardly be seen in a light microscope (also know as optical microscope). Corona viruses are much smaller than pandora viruses (about a quarter or less the size of a pandora virus).
The smallest object that can be viewed when using the best light microscope is about 0.25micron. This is known as the limit of resolution of an optical microscope, and can only be achieved with carefully chosen lighting, microscope objective and of course meticulous alignment. This means that YOU CAN NOT SEE VIRUSES using light microscopes, because they are too small.
However, there are special microscopes called electron microscopes that have been used to view tiny objects like viruses. They can magnify objects more than 10,000 times. The spiked balls images of corona virus being shown on your TV are the result of processing hundreds and hundreds of black and white (also known as grey-scale) images acquired from a cryo-electron microscope using special computer algorithms. A red blood cell acquired in a similar manner would be a giant with lots of fine structures being revealed.
Of course we know that such powerful electron microscopes are very expensive. Therefore, unlike malaria disease which is diagnosed by observing blood smear under light microscope, corona viruses can only be authentically proven to be present in a sample by a technique called Reverse Transcription quantitative Polymerase Chain Reaction (RT qPCR). RT qPCR amplifies the sample extracted from your respiratory tract and checks for the presence of SARS-COV2 Ribonucleic Acid (RNA).
