Pipette, what is it, price and how to choose it?

November 2, 2021

The pipette is a measuring tool or volumetric instrument. Despite the fact that, over the years, pipettes have evolved; The first pipettes created are very different from the current ones, the use of pipettes has been around for approximately 200 years. This is due to the development of disciplines such as chemistry and other disciplines that analyze fluids, disciplines that relied on measuring tools and machines to take small samples and analyze them.

There are records that tell of the invention of the first volumetric pipette, patented in 1924 in the United States. Clearly, pipettes were in use as early as 1790. Thanks to the first patent on the pipette, new modifications arose up to the modern pipette of today.

Among the most outstanding and innovative pipette creations is that of Gilson Pipetman, created in 1974, 50 years after the first patent, this allowed to adjust the volume. However, like most inventions, they had certain limiting details in the design, the main problem was that to use it it was necessary to apply a considerable force, pressing hard at the end; Another detail was that it did not withstand very high temperatures.

It was not until 1980 that they began to create models to solve the problems of the pipettes of the time, partially eliminating the cause of heating in the hand, as well as integrating pressure devices and / or springs. Currently the volumetric pipette has expanded working environments, not only in laboratories and in the chemical field, in some homes domestic types of pipettes can be used.

Now let’s define, what is a volumetric pipette?

The volumetric pipette is a measuring instrument that allows making measurements and calculating the volume of each of the substances; It has a cylindrical and hollow tank at one end, where the liquid is stored. Although pipettes can come in different capacities, they usually do not exceed 20ml. Most pipettes are made of glass and some are made of plastic.

The graduation of liquids in pipettes is measured in millimeters, in turn, each capacity has a corresponding error limit:

  • Capacity 2, error limit 0.006
  • Capacity 5, 0.01 error limit
  • Capacity 10, error limit 0.02
  • Capacity 30, error limit 0.03
  • Capacity 50, error limit 0.05
  • Capacity 100, error limit 0.08
  • 200 capacity, 0.010 error limit

The greater its capacity, the greater the error limit. This error limit defines the margin between the actual volume and the estimated volume; in this way, this instrument helps us to prevent errors, thanks to its unbreakable absolute value.

This instrument does not have a graduation as such, but rather a capacity, a seal that reveals the volume that the pipette loads. Pipettes can only hold a specific volume, however the liquid you measure will do so with extreme precision, more so than graduated pipettes.

What does it perform?

The function of the volumetric pipette is nothing more than to measure the body of liquids in a more precise way for analysis; the pipette calculates the proportion of the liquids, taking a proportional sample of the liquid with all its characteristics. The volumetric pipette is also used to take samples and analyze them or simply use them in different analyzes.

Where is the volumetric pipette used?

Among the main disciplines that use this instrument are chemistry, medicine and biology. Its use is for analytical purposes and when it is necessary to measure the precise value of a substance, such as in volumetry. It is also used to prepare solutions, especially to measure the proportion of the substances that compose it.

How should I use it?

To obtain accurate measurements of the liquids to be analyzed, it is necessary to learn how to properly use the volumetric pipette. The first step to follow is to sterilize the pipette so as not to contaminate the sample. The substance is extracted with a propipette that absorbs the liquid.

Normally the first suction of the liquid does not count, this is to make sure that the pipette has not left any impurities. After acquiring the sample, clean the pipette to remove any residual agent that could alter the next sample you are going to take. Once the pipette has been cleaned, proceed to level its contents.

When leveling, you level the gauge with the sample, exactly when the round of the liquid is level with that of the gauge. Always keep in mind that when flush is done parallel to the eyes, if not, you will create an optical effect that will make you believe that the liquid is level, when in fact it is not.

How is it calibrated?

Currently there are two types of calibration for volumetric pipettes, the first being to “pour” the samples; the pipette shows us a “TD”, “ex” or “vert”. The second calibration is to “contain”, in this, the pipette shows “TC”, “in” or “cont”.

Both calibrations are differentiated by the volume indicated by the calibration for pouring, which saves the volume of the poured liquid, this estimates the adherence of the sample around the pipette; the calibration to contain is according to the volume of the liquid that remains in the pipette.

To correctly calibrate a volumetric pipette you must follow the following steps:

  • Rest the pipette in distilled water at room temperature.
  • Weigh a precipitated container, calculating the error of the tenth of a milliliter.
  • Fill the pipette with distilled water and then transfer it to the precipitated container.
  • Calculate the volume of the liquid by weighing the precipitated container.
  • Do this process three times.
  • Then you compare the measurements by always calculating the measurements obtained.
  • Once the measurements are compared, it proceeds to calculate the consistency of the water, maintaining the temperature as the first measurements.

Calibration is very important in measuring instruments, when calibrating you establish the metrological properties in order to determine the recorded values ​​of a predetermined measurement. The volumetric pipette is calibrated for use in standard mode, applying predetermined temperatures and measurements; the usual temperature is necessarily 20 ° C because liquids expand when the temperature changes.

This measuring instrument is commonly used by specialists who work in areas where volume measurements, liquid transfers with high precision or sample analysis are carried out. For this reason, the pipette has a detailed and specific way of how to use it. However, using the pipette is not a difficult task.

Unique Features of the Pipette

Pipettes usually have a certain capacity, made of borosilicate glass and a tapered tip. The pipette itself is a tool that you can easily identify. The feature that stands out the most is the bag located on its tubular body.

The bag (or blister) comes in a specific size, it reveals how much volume it can absorb, following the bag, a small narrowing continues in the lower area. The size of the sachet will depend on the type of pipette. One more feature would be the capacity, they can come with two or just one. When it has a capacity, it is located on top of the bag; when there are two, the second is below.

Classes of volumetric pipettes or graduated pipettes

Today we have different types of pipettes, each one specializes in something and / or covers a need, such as the graduated pipette, which has graphs to measure different volumes. The Pasteur pipette, which transports liquids easily, but with less precision. If we talk about volumetric pipettes, two classes stand out, those that have two capacities and those that only have one.

The difference of each one is that pipettes with two gauges tend to be more exact in their measurements. They are used by leveling the liquid with the upper gauge, then letting it drain until the next gauge. Pipette classes are categorized by the liquid capacity they can hold and the level of precision.

Pasteur pipette

This pipette consists of a glass or plastic tube with a conical shape on the top tip similar to a balloon that blows air when squeezed. This pipette works when you need to transfer liquids that do not require much precision.

Graduated pipette (or simple gauge)

With it you can sample various types of liquids. It is leveled at 0 milliliters, then emptied reaching the desired volume.

Volumetric Pipette (double capacity)

Due to its unique upper erase, only a specific volume can be analyzed. The pipette is leveled with the upper gauge, then the liquid is carefully drained until it is parallel to the lower gauge.

This pipette stands out among graduated pipettes for its precision and, in the event that the conical tip becomes deformed, the volume is not affected.

How are pipettes important?

Graduated pipettes and volumetric pipettes are today the most efficient method of transporting just the right measure of a volume; pipettes cover a great need in laboratories, hospitals and all work spaces that carry out analyzes, as well as those that produce composite solutions.

Just like the graduated pipette and the volumetric pipette, there are different types of pipettes and measurement tools used in laboratories of all kinds, each one fulfilling a special function.

Dr. Loony Davis5
 | Website

Born and raised in Brussels in an English family, I have always lived in a multicultural environment. After several work experiences in marketing and communication, I came to Smart Water Magazine, which I describe as the most exciting challenge of my career.
I am a person with great restlessness and curiosity to learn, discover what I do not know, as well as reinvent myself daily, someone who is curious about life and wants to know. I enjoy sharing knowledge.
This is my personal project but I also collaborate in other blogs, it is the case, the most important web on water currently exists in the US, if you are interested you can read my articles here.

Leave a Reply

Your email address will not be published. Required fields are marked *