Traditionally, pipettes have been made of glass; in recent years, a variety of polymer materials have been increasingly used.

Medical pipettes

The most common pipettes are used to infuse drops of drugs (into the eyes, nose, or ears). Such pipettes consist of a piece of glass tube, one of the ends of the tube, strongly melted or drawn, has a small hole, and the other is closed with a flexible rubber (or polymer) container (tube, ball) and is designed to draw liquid into the pipette by suction.

In medical microbiology, there is also a special device - the Pasteur pipette (Pasteur pipette).

Measuring pipettes for chemical and biochemical research

Most often it is a glass vessel used to accurately measure (dispense) the volume of a liquid.

Various types of volumetric pipettes are available for a wide variety of purposes, with different classes of accuracy and for different volumes.

Traditional glass pipettes for analytical chemistry are available in two types:

• Mohr's measuring pipette(ungraded), for a given volume(1, 5, 10, 20, 50, 100, 200 ml, etc.) Mohr pipettes have one circular mark in the upper part and are intended for sampling liquids of a certain volume. Such pipettes usually provide a lower measurement error than graduated ones. GOST 29169-91 defines the permissible errors of pipettes. The error depends on the volume being measured, so a 25 ml pipette has a permissible measurement error of 25 ± 0.06 ml.
• graduated(usually cylindrical, 1, 2, 10 ml, etc.) For example, 5 ml pipettes are usually graduated through 0.5 ml. Graduated pipettes allow volume measurement, usually with an accuracy of ± 0.1 or 0.2 ml.

Mohr's single-label pipettes are sometimes referred to as aliquot pipettes.

Gas pipettes

Special pipettes

Rules for the use of glass pipettes

Pipettes are calibrated for free flow of liquid. You should not blow out or quickly squeeze out the liquid - in the first case, an excess volume will come out of the pipette, which should remain in its nose due to capillary forces, and in the second case, due to the leakage effect, the volume of the outflowed liquid will be less than the standard one.

Pipette calibration and pipetting accuracy

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An excerpt characterizing the Pipette

In the movement of the Russian army from Tarutin to Krasny, fifty thousand left sick and backward, that is, a number equal to the population of a large provincial town. Half of the people dropped out of the army without a fight.
And about this period of the campaign, when the troops without boots and fur coats, with incomplete provisions, without vodka, spend the night in the snow and at fifteen degrees of frost for months; when the day is only seven and eight o'clock, and the rest is night, during which there can be no influence of discipline; when, not like in a battle, for a few hours only people are led into the area of ​​death, where there is no longer discipline, and when people live for months, every minute fighting death from hunger and cold; when half of the army perishes in a month - historians tell us about this period of the campaign, how Miloradovich had to make a flank march there, and Tormasov there, and how Chichagov had to move there that (move above the knee in the snow), and how that knocked over and cut off, etc., etc.
The Russians, who were half dying, did everything that could and should have been done to achieve a goal worthy of the people, and it is not their fault that other Russian people, sitting in warm rooms, assumed to do what was impossible.
All this strange, now incomprehensible contradiction of fact with the description of history occurs only because the historians who wrote about this event wrote the history of the wonderful feelings and words of different generals, and not the history of events.
For them, the words of Miloradovich, the awards that this and this general received, and their assumptions seem very amusing; and the question of those fifty thousand who remained in hospitals and graves does not even interest them, because it is not subject to their study.
Meanwhile, one has only to turn away from studying reports and general plans, but to delve into the movement of those hundreds of thousands of people who took a direct, direct part in the event, and all that seemed insoluble before, questions suddenly get undoubtedly resolved with extraordinary ease and simplicity.
The purpose of cutting off Napoleon with the army never existed, except in the imagination of a dozen people. It could not exist because it was meaningless and it was impossible to achieve it.
The goal of the people was one: to cleanse their land from the invasion. This goal was achieved, firstly, by itself, since the French fled, and therefore it was only necessary not to stop this movement. Secondly, this goal was achieved by the actions of the people's war, which destroyed the French, and, thirdly, by the fact that a large Russian army followed the French, ready to use force if the French movement stopped.
The Russian army was supposed to act like a whip on a running animal. And an experienced driver knew that the most advantageous thing was to keep the whip raised, threatening them, and not to lash a running animal on the head.

When a person sees a dying animal, horror seizes him: what he himself is - his essence, in his eyes is obviously destroyed - ceases to be. But when a dying person is a person, and a beloved person is felt, then, in addition to the horror of the destruction of life, a rupture and a spiritual wound is felt, which, like a physical wound, sometimes kills, sometimes heals, but always hurts and is afraid of an external annoying touch.
After the death of Prince Andrei, Natasha and Princess Marya felt this equally. They, morally bent over and screwing up their eyes from the formidable cloud of death hanging over them, did not dare to look into the face of life. They carefully guarded their open wounds from offensive, painful touch. Everything: a carriage quickly drove along the street, a reminder of dinner, a girl's question about a dress that needs to be prepared; even worse, the word of insincere, weak sympathy painfully irritated the wound, seemed an insult and broke that necessary silence in which they both tried to listen to the terrible, strict chorus that had not yet heard in their imagination, and prevented them from peering into those mysterious endless distances that for a moment opened In front of them.
Only the two of them were not offended or hurt. They spoke little to each other. If they talked, it was about the most insignificant subjects. Both the one and the other equally avoided mentioning anything related to the future.
To admit the possibility of the future seemed to them an insult to his memory. Even more carefully they avoided in their conversations everything that could be related to the deceased. It seemed to them that what they experienced and felt could not be expressed in words. It seemed to them that any mention of the details of his life in words violated the greatness and sanctity of the sacrament that had taken place in their eyes.
The incessant abstinence of speech, the constant diligent circumvention of everything that could suggest a word about him: these stops from different sides on the border of what could not be said, even clearer and clearer exposed before their imaginations what they felt.

But pure, complete sorrow is as impossible as pure and complete joy. Princess Marya, by her position as one independent mistress of her fate, guardian and educator of her nephew, was the first to be called by life from that world of sorrow in which she lived for the first two weeks. She received letters from relatives to which she had to answer; the room in which Nikolenka was placed was damp, and he began to cough. Alpatych arrived in Yaroslavl with business reports and with suggestions and advice to move to Moscow to the Vzdvizhensky house, which remained intact and required only minor repairs. Life did not stop, and one had to live. No matter how hard it was for Princess Marya to leave that world of solitary contemplation in which she had lived until now, no matter how sorry and as if ashamed it was to leave Natasha alone, the worries of life demanded her participation, and she involuntarily gave herself up to them. She checked the scores with Alpatych, consulted with Desal about her nephew and made orders and preparations for her move to Moscow.

With a tube having an end (tip, tip, spout) with a small hole to limit the rate of fluid flow.

A variety of pipettes are widely used for measuring precise volumes of liquids or gases, in medicine, chemistry and biology, and especially widely in analytical chemistry and biochemistry.

Pipette types

Traditionally, pipettes have been made of glass; in recent years, a variety of polymer materials have been increasingly used.

Medical pipettes

The most common pipettes are used to infuse drops of drugs (into the eyes, nose, or ears). Such pipettes consist of a piece of glass tube, one of the ends of the tube, strongly melted or drawn, has a small hole, and the other is closed with a flexible rubber (or polymer) container (tube, ball) and is designed to draw liquid into the pipette by suction.

In medical microbiology, there is also a special device - the Pasteur pipette (Pasteur pipette).

Measuring pipettes for chemical and biochemical research

Manual micropipette

Most often it is a glass vessel used to accurately measure (dispense) the volume of a liquid.

Various types of volumetric pipettes are available for a wide variety of purposes, with different classes of accuracy and for different volumes.

Traditional glass pipettes for analytical chemistry are available in two types:

• Mohr's measuring pipette(ungraded), for a given volume(1, 5, 10, 20, 50, 100, 200 ml, etc.) Mohr pipettes have one circular mark in the upper part and are intended for sampling liquids of a certain volume. Such pipettes usually provide a lower measurement error than graduated ones. GOST 29169-91 defines the permissible errors of pipettes. The error depends on the volume being measured, so a 25 ml pipette has a permissible measurement error of 25 ± 0.06 ml.
• graduated(usually cylindrical, 1, 2, 10 ml, etc.) For example, 5 ml pipettes are usually graduated through 0.5 ml. Graduated pipettes allow volume measurement, usually with an accuracy of ± 0.1 or 0.2 ml.

Mohr's single-label pipettes are sometimes referred to as aliquot pipettes.

Gas pipettes

Special pipettes

Rules for the use of glass pipettes

Pipettes are calibrated for free flow of liquid. You should not blow out or quickly squeeze out the liquid - in the first case, an excess volume will come out of the pipette, which should remain in its nose due to capillary forces, and in the second case, due to the leakage effect, the volume of the outflowed liquid will be less than the standard one.

The section is very easy to use. In the proposed field, just enter the desired word, and we will give you a list of its meanings. I would like to note that our site provides data from various sources - encyclopedic, explanatory, word-formation dictionaries. Also here you can get acquainted with examples of the use of the word you entered.

Pipette

eyedropper in the crossword dictionary

Dictionary of Medical Terms

pipette (French pipette)

device for measuring a certain volume of liquid or gas;

glass tube, tapered at one end, for measuring liquid droplets.

Explanatory dictionary of the Russian language. D.N. Ushakov

pipette

pipettes, f. (French pipett - tube) (special). Narrow glass tube with rubber tip for aspirating, drawing in a small amount of liquid and releasing it in droplets back. Eyedropper for eye drops. Ink dropper (edges are used to pour ink into the eternal nib).

Explanatory dictionary of the Russian language. S.I.Ozhegov, N.Yu.Shvedova.

pipette

And, well. Glass tube with a rubber cap for measuring the liquid drop by drop, dropper (3 values). P. for eye drops. Dispense with a pipette.

adj. pipette, th, th.

New explanatory and derivational dictionary of the Russian language, T. F. Efremova.

pipette

f. A small glass tube with a rubber tip for drawing in, drawing in liquid and discharging it in drops.

Wikipedia

Pipette

Pipette- a measuring or dosing vessel, which is a tube, or a container with a tube having an end with a small hole to limit the rate of fluid outflow.

A variety of pipettes are widely used for measuring precise volumes of liquids or gases, in medicine, chemistry and biology, and especially widely in analytical chemistry and biochemistry.

Examples of the use of the word pipette in the literature.

Holders, test tubes, conical flasks, allongee, retorts, cylinders, agate mortars, porcelain crucibles from the royal factory in Sevres, crystallizers ordered from Lavoisier's drawings to the Venetian glass factory on the island of Murano , graded pipettes, scales, burettes, cuvettes - all this fantastic glass world, at the behest of the scientist, advancing on avaricious nature, breaking its secrecy, burned and sparkled in the sun of a Parisian evening, shimmering with colored lights, the rainbow play of a sunbeam, so simple and white, decaying with joy for a thousand color overflows in the laboratory of Antoine Lavoisier as if above, where Madame Pauce reigns, again turn into austere, white and colorless, even as if it has become mean, sunlight.

The first-aid kit should contain: dressing materials - cotton wool, bandages, sterile gauze napkins, mustard plasters, a thermometer, waxed compress paper, a glass for taking medications, an eye pipette, fingertips.

The donuts were rearranged into a continuous arc, from which a soloist, a laboratory assistant of a senior researcher from the department of organophosphorus compounds, stepped forward two steps forward: pipette.

When Oscar got up from the table, Meisner told the doctor who was dripping from pipettes medicine in a glass: - Go.

TO pipette, a test tube, a spoon and a stirrer - devices that allow the perfumer to master the complex process of mixing Grenouille has never touched.

Fat man with pipette while Nuri bargained, he stood aside and watched with obvious pleasure.

At the request of the cyber, Jafar dripped from pipettes on the removed cover, and the spider kept dropping the tip of the manipulator into the puddle, transferring a drop of lubricant into the mechanism.

A quarter of an hour later, Jafar returned from pipette and generously watered the spider's manipulators, hoping that the grease would get where it needed to be.

Plastic pipette was kept in my shoe, a safety pin stuck in my belt.

To find out, he, Baldini, would have to experiment for several days in a row - a terrible job, perhaps even worse than simple identification of parts, because he had to measure, and weigh, and write down, and at the same time be devilishly attentive, for the slightest carelessness - trembling pipettes, an error in the count of drops - could ruin everything.

V pipette there remained an iridescent thin film of blood, and the white paper collar was soaked all over with it, like a bandage.

I just want to draw the attention of readers to the fact that the investigating authorities considered it necessary to question in detail precisely the former officers of the detachment about the poison and pipette, about the actions of the offender, his age and signs.

Then, with calm and at the same time quick movements, he took it off the small shelf and brought the utensils necessary for the experiment: a large pot-bellied milk bottle, a glass funnel, pipette, small and large beakers - and in exemplary order placed it all in front of him on an oak lid.

Then, without haste, he took pipette- such a glass tube, with a small rubber cap at the end, which is usually buried in the eyes.

I ran to the closet, grabbed a bottle of drops pipette and began the most important operation of the day.

Pipettes are glass tubes of all diameters. Pipettes can be either straight or with an extension in the middle, which can be of three types: cylindrical, spherical, pear-shaped.

Pipette types:

1) a pipette with an extension and a label, called the Mohr pipette;

2) a pipette graduated to full drain and equipped with a canonical end;

3) a pipette, graduated to full drain, with a flat end;

4) pipette graduated to partial discharge with canonical or flat end;

5) blown pipettes.

The graduated pipette was created by the German chemist and pharmacist Karl Friedrich Mohr (1806-1879). These pipettes are used to partially drain a set amount of liquid. For a unit of volume, cm3 or ml is taken.

Graduated pipettes are classified into two accuracy classes:

1) class A is assigned to high-level pipettes, the marginal error is several times less than the minimum scale division value;

2) class B pipettes have a low level, while the marginal error in measuring the volume should be less than the minimum scale division value, for example, 0.01 ml for pipettes with a volume of 1 ml and 0.2 ml, respectively, for pipettes of 5 ml.

The type of pipettes also determines where the liquid is poured from the pipette; this can be carried out from the zero line at the top to any graduation line. In other cases, pour out from any graduation line to the spout. The upper part of the pipette necessarily creates a right angle with the axis of the pipette, defects on it are excluded, since they can interfere with the precise setting of the meniscus with the help of a finger. The bottom of the pipette is a smooth cone-shaped pouring nozzle. To establish the meniscus of the fluid, it is necessary to create a coincidence of the plane of the upper edge or center of the graduation line with the lower point of the meniscus itself. To eliminate or at least reduce them to a minimum, one method of setting the meniscus is used to study the initial and final values. The installation of the descending meniscus is done in a certain way: a clean pipette is taken, which is held in an upright position, it is filled with liquid, which should be about a few millimeters above the graduation line, and a meniscus is set on this line. To remove a drop that may remain on the tip of the pipette, a glass vessel is used, as a result of touching it with the tip of the pipette, the drop is removed. From a pipette, the liquid is poured into a glass vessel, which is fixed in a slightly tilted state, while the tip of the spout should touch the inner surface of this vessel. The pipette and vessel do not move during the draining procedure. The pouring out time for 10 ml pipettes is 10 s, for 5 ml pipettes should not be more than 1 s. In the case where the pipette is not provided with an indication of the drain-off time-out, it is not necessary to wait for the complete drainage of the liquid that may remain on the walls. For completeness of pouring to the spout, the waiting time is 3 s. In the case when a waiting time is indicated, for example 15 s, pouring stops when the meniscus is above the graduation line by a few millimeters. The meniscus is finally fixed in 15 s on the graduation line. If the pouring is carried out completely to the spout, then it is kept for 15 s until the pipette is removed from the receiving vessel. For blow pipettes, be sure to blow the last drop out of the nozzle.

A high-precision pipette is used for serial pipetting of various volumes - 12.5 μl, 25 μl, 50 μl. The pipetting accuracy for this type of pipette is ± 2.0% for 12.5 μL, ± 1.5% for 5 μL, and ± 1.5% for 50 μL. Such pipettes are easy to use and are designed for use by both right-handed and left-handed people. Equipped with disposable tips and tip ejectors.

They are used for making accurate metering of a set volume of liquid, as well as for transferring liquid from one vessel to another. Pipettes are designated by a certain sequence of numbers, between which hyphens are placed. The numbers carry certain information: pipette type - performance - accuracy class - volume (for example, 1 - 2 - 5 - 10). Pipettes must be calibrated for pouring, the accuracy must correspond to a specific sample of the standard. Also, the pipettes can indicate the temperatures at which the pipette was calibrated, the designation for pouring the indicated container and the waiting time, if specified, the volume measurement error limits.

The accuracy of laboratory research results largely depends on the used laboratory glassware, laboratory equipment and instruments. They must be of high quality and comply with GOST standards. The main requirement for their selection is strict application for the intended purpose in compliance with all recommendations for use. It is also important to take into account their physical and chemical characteristics: heat resistance, impact resistance, moisture resistance, resistance to interaction with chemical reagents - acids, alkalis and other aggressive compounds.

Among the huge variety of laboratory glassware, a special place is occupied by measuring and dosing vessels made of laboratory glass. They are designed to measure precise volumes of liquid and gaseous substances. The simplest and most common among this arsenal is the pipette. Its scope covers almost all branches of science and industry: biology, chemistry, medicine, pharmaceuticals, etc.

Concept and types of pipettes

A pipette is a container in the form of a narrow tube with a tip or a tip with a small opening to regulate the flow rate of the substance. For many decades, glass has been the main material for making pipettes, but recently, with the development of industry, new, alternative materials have emerged: plastic, crystalline polystyrene, and others. Plastics measuring instruments are usually disposable. Its main advantage is that it does not require time and costs for sterilization, since it is supplied already sterilized under the influence of gamma radiation. This makes it more accessible and relatively inexpensive.

Commonly used disposable measuring devices include serological pipettes. During their production, international color coding is strictly observed, depending on the volume. The dosage accuracy allows an error of no more than 0.1 ml or 2% of the volume. In addition, there is a negative graduation of the additional working volume. Serological pipettes are made of high quality, non-toxic polystyrene. They are compatible with both automatic and manual dispensers. The big advantage for these pipettes is the complete drainage of the liquid and the guarantee against leakage due to the unique seamless design (one-piece tube).

In addition to the contained volume, serological pipettes also differ in the shape of the nozzle. They can be narrowed, open and normal.

Depending on the purpose and scope of application, pipettes are:
- medical;
- measured for biochemical research;
- micro;
- gas;
- special.

Medical pipettes

This type of pipette is used for infusion of medicinal solutions in the form of drops into the eyes, ears, nose. By its structure, it is the most primitive. It is used both in medical institutions of various profiles and at home. It consists of a glass tube with a flexible rubber or polymer tip at the end.

It has found particular application in medical microbiology. It is designed to collect micro-doses of raw materials for sowing. Although disposable (polymer) pipettes are currently used, which are safe and convenient to use, in analytical biology, laboratory glass products are more preferable, since they have a number of advantages:
- high transparency;
- chemical and thermal stability;
- multiple use.

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