What Are The Direct Methods Of Studying Unstained Specimens And Their Specific Purposes?


1 Answers

Connor Sephton Profile
Connor Sephton answered
There are two main methods of studying specimens that doesn't involve staining the specimen that you are trying to look at properly. These methods are:

• Dark field microscopy.

Dark field generally occurs in study sessions when the objects being studied are living specimens in a pond or water source. It can bring about really good images of smaller organisms like plankton, small worms and single celled animals. With dark field microscopy, the unscattered beam from the image is excluded, resulting in the field around the specimen looking dark. This explains the name of dark field as it makes everything around the specimen seem dark, as it is the field.

• Phase contrast microscopy

Phase contrast differs to dark field microscopy as it instead uses higher power and studies matter such as bacteria. This method is seen as an optical illusion as it passes light through a transparent organism or specimen and creates contrast changes within the image of the specimen in question.  Phase contrast made it possible for single cells to be looked at properly, bringing about the study of the cell cycle. When light travels through anything that isn't a vacuum, the contrast will occur with amplitude depending on the properties of the medium that is being studied.

Staining can result in the specimen being ruined, meaning that these types of methods above are incredibly important in some studies, especially in the case of the cell cycle research. Staining is also a very finicky difficult job to do, meaning that microscopes that do not require a stained specimen are much less time consuming to use and mean that you get more time to properly look at the specimen that you are studying.

Answer Question