Pipetting Techniques and Calibration

<p>The properties of the compounds in the solutions. (D)</p> Signup and view all the answers

<p>They repel the sample being pipetted. (C)</p> Signup and view all the answers

<p>To dispense accurate and precise volumes of solutions (A)</p> Signup and view all the answers

<p>Serial number and make of the pipette (B)</p> Signup and view all the answers

<p>Regularly, in accordance with guidelines (B)</p> Signup and view all the answers

<p>A 5 place balance (B)</p> Signup and view all the answers

<p>Within 3% of expected weight (A)</p> Signup and view all the answers

<p>Multi-channel pipettes (A)</p> Signup and view all the answers

<p>To check the maintenance history and calibration details (C)</p> Signup and view all the answers

<p>Helps in tracking maintenance and calibration (C)</p> Signup and view all the answers

<p>Touch the tip against the side of the receiving vessel. (A)</p> Signup and view all the answers

<p>Air displacement pipette with a filter. (A)</p> Signup and view all the answers

<p>Glycerol. (C)</p> Signup and view all the answers

<p>Dispense against the side of the receiving vessel at a slight tilt. (A)</p> Signup and view all the answers

<p>With a soft cloth and water. (D)</p> Signup and view all the answers

<p>Aspiring and dispensing at a slow and consistent speed. (C)</p> Signup and view all the answers

<p>50-100% of the pipette's max capacity (C)</p> Signup and view all the answers

<p>Positive displacement pipette. (A)</p> Signup and view all the answers

<p>Ethanol or IMS. (D)</p> Signup and view all the answers

<p>Get a second person to perform the calibration (C)</p> Signup and view all the answers

<p>When the sample must remain sterile (B)</p> Signup and view all the answers

<p>To prevent leakage during pipetting (C)</p> Signup and view all the answers

<p>Increased risk of inaccuracy (A)</p> Signup and view all the answers

<p>Replace it immediately (A)</p> Signup and view all the answers

<p>Send it to the manufacturer for repair (C)</p> Signup and view all the answers

<p>Racked tips reduce contamination risk (D)</p> Signup and view all the answers

<p>When preparing a calibration line and moving up in concentration (D)</p> Signup and view all the answers

<p>Prime or pre-wet the tip with the solution you wish to transfer (C)</p> Signup and view all the answers

<p>They maintain constant aspiration force regardless of sample properties (A)</p> Signup and view all the answers

<p>Below the meniscus but away from the sides (D)</p> Signup and view all the answers

<p>To ensure complete liquid transfer (A)</p> Signup and view all the answers

<p>To prevent contamination between samples (A)</p> Signup and view all the answers

<p>Depressing the plunger quickly (C)</p> Signup and view all the answers

<p>It can dispense variable volumes with high precision (B)</p> Signup and view all the answers

The practice of using pipettes to accurately dispense liquids, especially in laboratory settings.

A unique identifier assigned to each pipette, often including the area or assay it is used for and a number.

The process of verifying the accuracy and precision of a pipette using calibration standards. Typically done using water weighings or radioactive solutions.

A set of guidelines or procedures that outline how to use and maintain laboratory equipment, including pipettes.

The ability of a pipette to dispense the same volume of liquid consistently.

The ability of a pipette to dispense the correct volume of liquid.

A measure of how close a pipette's dispensed volume is to the expected volume, typically expressed as a percentage.

A measure of how consistent a pipette's dispensing is, typically expressed as a percentage.

The lowest and highest volumes a pipette is designed and calibrated to dispense.

The optimal range for using a variable volume pipette is between 20% and 100% of its maximum capacity.

When using variable volume pipettes, it is important to select a pipette that allows for the desired volume to fall within a specific range of the pipette's overall capacity. The ideal volume should be between 50% and 100% of the pipette's maximum volume.

The pipette tip used should be specifically compatible with the make and model of the chosen pipette.

For applications requiring sterility or protection from contamination (e.g. plasma, cell cultures, next generation sequencing), pipette tips with filters can be employed to prevent liquids from reaching the pipette barrel.

Pipette calibration should be checked regularly. If issues persist after thorough inspection, it is recommended to consult a second individual or seek service from the manufacturer or a reputable service provider.

Ensure the chosen pipette tip is of high quality, free from defects, and leaks. Also, check for any air bubbles within the tip before pipetting.

Always check the tip used on a pipette to ensure it is securely fitted and not damaged or leaking.

If a pipette fails calibration after carefully checking for common issues, it is essential to thoroughly clean it. This includes removing any residual contaminants and applying lubricant to maintain proper movement.

Liquid properties like viscosity and volatility can affect the accuracy and precision of pipetting.

Air-displacement pipettes are ideal for water-based liquids, while positive-displacement pipettes are better for challenging liquids like viscous, volatile, corrosive, or biological samples.

To avoid sample loss, gently touch the pipette tip against the receiving vessel's side to transfer any remaining droplets from the tip.

Consistent pipetting speed helps maintain accuracy and reproducibility of the results.

Holding the pipette at a slight angle during dispensing helps to control the liquid flow and minimize air bubbles.

Always remove any droplets on the outside of the pipette tip before dispensing to avoid introducing extra liquid.

Using the same pipette tip for multiple samples of increasing concentrations, ensuring each solution is drawn into the tip before dispensing. This minimizes the risk of contamination when preparing a calibration line.

A pipette designed to draw liquid into the tip by displacing the air inside the tip. The plunger pushes the air out and draws the liquid in.

A pipette that uses a piston to directly displace the liquid being dispensed. It has no air cushion, making it ideal for viscous or dense liquids.

The process of rinsing the pipette tip several times with the same liquid to ensure accurate dispensing. It removes any residual liquid from previous samples.

The point on the pipette tip where the liquid level should be drawn up to. It's typically the bottom of the meniscus.

The practice of holding the pipette vertically while drawing liquid into the tip. This ensures consistent aspiration and decreases the chance of air bubbles.

Depressing the plunger to a specific point during dispensing to expel all the liquid from the tip. This ensures complete liquid transfer.

The act of carefully placing the pipette tip into the desired liquid sample. The tip should be submerged below the meniscus but not touch the bottom of the container.

Using organic solvents to clean a pipette can cause damage or corrosion.

Pipettes should be stored vertically on a stand or carousel to prevent contamination and damage.

When a pipette is dropped or disassembled, it must be recalibrated to ensure accuracy.

Use separate sets of pipettes for different lab procedures (e.g., radioactivity, cell culture) to prevent cross-contamination.

Some compounds can stick to pipette tips or sample vessels, affecting pipetting accuracy.