Pipetting and Calibration

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Objective

Students will be able to perform a micro- and macropipette calibration using the gravimetric method in order to determine the accuracy and precision of our micropipettes.

Big Idea

Calibration of our pipettes in the biotechnology laboratory enables us to become aware of the difference between dispensed volume and the selected volume which may be a source of unknown error.

Introduction

5 minutes

Micropipettes are used extensively in molecular diagnostics to accurately and precisely deliver small volumes of liquid.  The correct use of micropipettes is essential to ensure accurate volume delivery and to prevent damage to these expensive pieces of equipment.  It is crucial that, prior to use, the student become familiar with function of the parts, function and use of the micropipette.

Lesson Materials:

- Micropipette Calibration Pre-Lab Activity

- Micropipette Calibration Technique Practice

- Micropipette Calibration Performance Assessment

- Digital Course Guide

- P-10, P-20 micropipette

- 1.5 mL microcentrifuge tubes

- Pipette tips

- Analytical Balance

- Taring containers

- Water

- Serological Pipettes (1mL, 2mL, 5mL)

- Distilled Water

- Food Coloring

Engage

15 minutes

In order to determine or assess student's prior knowledge, all students will complete pre-lab guided practice individually and then verify responses to the tasks in pairs. During a whole group discussion students are encourage to surface areas where they struggled as well as areas in which they feel confident and may they have exhibited mastery.

Explore

20 minutes

In order to complete this portion of the lab exercise, students should be placed in groups of 3-4 students. Each lab group will be provided a P-20 pipette in addition to several 1.5 mL microfuge tubes filled with 1.0 mL of distilled water and food coloring. Each student will take turns pipetting the volumes indicated on the Micropipette Calibration Technique Practice using the colored solutions.

Explain

20 minutes

Students will complete the pipetting and calibration performance assessment in pairs or small group of no more than three students. The goal of this portion of pipetting practice is to enable students to see the connection between their personal pipetting technique, the operation of this important instrument and the calibration technique that informs technologists of the accuracy and precision of this tool.

On Page 3 of the performance assessment, students will complete the calibration portion of the lab practice and prepare the report on Page 5 of the performance assessment.

Elaborate

20 minutes

At the conclusion of the performance assessment, each student should complete the Pipette Calibration Report located on Page 5 which enables students to perform statistical analysis such as standard deviation and percent error in order to quantitatively determine the accuracy and precision of their pipetting technique and proper calibration of their pipetting tools! 

Evaluate

15 minutes

Students complete the digital course guide along with the online pipetting course via NCCC BioNetwork. Students will earn a lab training certification with successful completion of the online course assessment. As an additional check for understanding students can complete an exit ticket in which they summarize the coaching suggestions they feel is necessary for each employee to improve their pipetting practice!