What is the Difference Between Volumetric and Serological Pipettes

The key difference between volumetric and serological pipettes is that volumetric pipettes are calibrated to deliver a certain volume of a solution through free drainage, whereas serological pipettes are calibrated all the way to the tip, and the last drop of the solution has to be blown out.

Pipettes are very important and regularly used analytical instruments in laboratory work. These are important in carefully measuring liquids.

CONTENTS

1. Overview and Key Difference
2. What are Volumetric Pipettes
3. What are Serological Pipettes 
4. Volumetric vs Serological Pipettes in Tabular Form
5. Summary – Volumetric vs Serological Pipettes 

What are Volumetric Pipettes?

Volumetric pipettes are analytical instruments that are important in obtaining extremely accurate measurements of the volume of a solution. These are also known as bulb pipettes or belly pipettes. This pipette gives its measurement to four significant figures. We can calibrate this instrument to deliver an accurate and fixed volume of liquid.

There is a large bulb in this type of pipette along with a long narrow portion above it. There is a mark on this long narrow part to which the instrument is marked for a single volume value. This is similar to the calibration of a volumetric flask. Typically, the values that are available include 1, 2, 5, 10, 20, 25, 50, and 100 ml. Commonly, volumetric pipettes are useful in analytical chemistry in order to prepare laboratory solutions using a base stock and also to prepare solutions for titrations.

There is a specific type of volumetric pipette named micro-fluid pipette. It is capable of measuring very small amounts of liquids, which are as small as 10 microliters. These pipettes are designed with a circulating liquid tip that can generate a self-confining volume in front of the outlet channels.

What are Serological Pipettes?

Serological pipettes are nearly ubiquitous laboratory instruments that are useful for the transfer of milliliter volumes of liquid. We can use this type of pipettes when transferring liquids between receptacles, when mixing chemical solutions, and also when laying reagents consisting of different densities. This type of process requires great attention to detail when it is applied for aspirating and dispensing of the solution.

These pipettes are temperature-calibrated analytical instruments that are ideal for laboratory works. Mainly, these are important in transferring large amounts of liquids. The design of these pipettes includes materials such as plastic, sterile, reusable materials, and glass.

What is the Difference Between Volumetric and Serological Pipettes?

Pipettes are very important and regularly used analytical instruments in laboratory work. These are important in carefully measuring liquids. The key difference between volumetric and serological pipettes is that volumetric pipettes are calibrated to deliver a certain volume of a solution through free drainage, whereas serological pipettes are calibrated all the way to the tip, and the last drop of the solution has to be blown out.

The below infographic presents the differences between volumetric and serological pipettes in tabular form for side by side comparison.

Summary – Volumetric vs Serological Pipettes

Volumetric pipettes are analytical instruments that are important in obtaining extremely accurate measurements of the volume of a solution. Serological pipettes are nearly ubiquitous laboratory instruments that are useful in the transfer of milliliter volumes of liquid. The key difference between volumetric and serological pipettes is that volumetric pipettes are calibrated to deliver a certain volume of a solution through free drainage, whereas serological pipettes are calibrated all the way to the tip, and the last drop of the solution has to be blown out.

Reference:

1. Hosford, Victoria. “Serological Pipette: Is It What Your Lab Needs?” Pipette.com, Victoria Hosford.

Image Courtesy:

1. “Vollpipetten” By Gmhofmann – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Serological pipette and accuracy level” By Paweena.S – Own work (CC BY-SA 4.0) via Commons Wikimedia