SEROLOGICAL PIPETTE: CHARACTERISTICS AND USES - CHEMISTRY - 2024

The serological pipette is a type of sterile pipette that is mainly used for cell culture and / or work with sterile solutions. It is a type of graduated pipette also called terminal pipette, since the graduations occupy the entire surface of the pipette, including the tip. This differentiates it from the rest.

This pipette allows the transfer of very small volume proportions of liquids, ranging from 0.1 ml to 50 ml. It is designed in different sizes, to be used according to the need of the manipulator. However, some bibliographies state that they are ideal for transferring volumes between 5 ml and 25 ml.

Sterile pipettes are usually individually wrapped in Kraft paper, and there are correct techniques to remove sterile pipettes if several are contained in the same container without contaminating the rest of the pipettes.

Main features

They are part of the pipettes

Serological pipettes have the characteristic of being considered within the group of blow-out pipettes. A blowing pipette is one in which the capacity described on its surface does not take into account that part of the liquid adheres to its walls after pouring it into the container.

This liquid is part of the volume to be dispensed. Therefore, in order to obtain the entire volume described, the pipette must be blown to expel that remaining liquid and obtain the precise quantity indicated by the pipette in the receiving container.

Open top end

To expel the liquid, these pipettes have their upper end open, their structure resembling a straw or straw. Through this hole, the manipulator can create a vacuum by placing his finger and thus keep the liquid inside the pipette.

In the same way, after pouring the contents of the pipette into the receiving container, it is possible to blow on the open end to pour the last drops of liquid adhered to the walls of the pipette, to ensure that the entire volume indicated by the pipette is poured..

Frosted belt

This type of pipette is identified by a frosted belt near its upper end or by two thin colored rings around the neck of the pipette.

Recommended filling with a pipette

Although some serological pipettes are blown, the use of a propipette for filling is suggested. This is because, due to the small amounts it carries, it is difficult for the user to control the sucked liquid when performed with the mouth.

Applications

To transfer volumes of body fluids

As its name indicates, it is the pipette used for the transfer of volumes of fluids from body fluids, for the study of pathogens and antibodies, among other elements.

Because the serological pipette can be used for the transfer and measurement of liquids with potentially pathological gases for the technician or the environment, they bring with them a small filter to prevent pathogens from coming into contact with the atmosphere.

In the food and cosmetic industry

It is also frequently used in food production and the cosmetic industry. It is used when the volumes to be transferred are very small, and it is recommended to use the smallest possible scale to avoid errors in the required volume.

For example, if it is necessary to transfer 0.9 ml, the use of a 1 ml pipet is recommended instead of a 10 ml pipet.

Differences between serological pipet and volumetric pipet

Liquid volumes

The main difference is that the serological pipette is a graduated pipette that allows transferring various volumes of liquids with the same pipette as required. In contrast, the volumetric pipette only allows you to measure a single volume.

This feature makes the volumetric pipette much more accurate and precise than the serological pipette.

Blown

The serological pipette is marked so that some can be blown or blow out. That is, after pouring the liquid it must be blown through the upper end to see the rest of the liquid adhering to the walls.

However, no volumetric pipette allows subsequent blowing. Whether pouring or holding pipettes, the capacity described on the pipette surface should be considered by the technician who selected the pipette.

Articles of interest

Graduated pipette.

Beral pipette.

Volumetric pipette.

References

1. JoVE Science Education Database. General Laboratory Techniques. Introduction to Serological Pipettes and Pipettors. JoVE, Cambridge, MA, (2018). Recovered from: jove.com
2. Micah McDunnigan. Different types of pipettes. February 1, 2018. Geniolandia. Recovered from: geniolandia.com
3. Evelyn Rodríguez Cavallini. General Bacteriology: Principles And Laboratory Practices. Serological pipettes. Page 11. Recovered from: books.google.pt
4. In cell culture, Lab equipment, molecular biology, Pipet, sterile on March 2, 2009. Using Serological Pipettes. Labtutorials in Biology. Recovered from: labtutorials.org
5. Practical biochemistry. Accuracy in the laboratory. Graduated pipettes. Page 13. biochemistry.dogsleep.net