Running an Effective Laboratory Session

Author: Dr. Saphida Migabo (Biology)

One of the duties of a laboratory teaching assistant is to lead laboratory sessions. Depending on the program, these could be one or more sessions. Your responsibilities will depend on whether you are co-teaching the lab with the Course Instructor(s) or the Senior Laboratory Instructor (SLI) in charge of the class or you are on your own. The following are some suggestions to help you run your lab session.

Advance Preparation

  • If this is your first lab session, visit the lab room to familiarize yourself with the layout, equipment and supplies available.
  • If you are teaching for the very first time, make sure you have completed the mandatory chemical and biosafety training.  Check the laboratory Safety website for details.
  • For each weekly session, read the lab exercises. Depending on the complexity of the lab, you may want to read the lab several times. Make sure you understand the objectives and learning outcomes of the exercise.
  • Know your subject. If the topic is unfamiliar or you are a bit rusty do some background reading.

• Meet with your supervisor to verify lab procedures, availability of supplies and so forth. Note any changes that students need to made aware of.

• If your supervisor has not provided you with a lab outline to follow, prepare your own. Prepare questions and examples to work from during the lab.

  • If you are required to present a pre-lab presentation, prepare one several days before the scheduled lab session.  This will allow you time to review it and become comfortable with the material.

Prep Session

• Confirm that you have all the necessary materials and equipment in the lab.

• Familiarize yourself with procedures and equipment the students will use for the exercise.  Do not assume that materials and techniques are basic and you will have no trouble teaching them.

• It is strongly recommended that you are comfortable with all calculations the students will be performing.

• Familiarize yourself with lab safety protocols and know the location of all safety equipment such as fire extinguishers, exit, showers and eye wash stations.

• Read the Material Safety Data Sheets (MSDS), if the lab involves the use of chemicals.

  • Familiarize yourself with all biosafety procedures if applicable for each exercise.

• If there are things you can do before the lab, such as setting equipment, do it at this time.

During the Lab

  • Start your lab on time.
  • Make any important announcement regarding the current or previous labs at the beginning of your session.
  • If you have any assignments to hand back, you can do it at the beginning, during the session or at the end of the session.
  • Pre-lab talk: Be prepared to give an effective presentation to the students regarding the lab activities. What to include in the presentations largely depends on the lab. Keep the pre-lab talk to a minimal (10-20 minutes) to allow enough time for students to complete the experiments. Include the following in your pre-lab talk.
    • Introduce the experiment. This may include providing background information such as relevant theories or concepts. You can use the whiteboard, overheads or PowerPoint if available.
    • Remind students of the objectives of the lab.
    • Relate theory to the lab objectives.
    • As much as possible, relate the experiment to real world applications. This helps student see the importance of the experiment and enhances their learning.
    • Provide a brief overview of what the students will do.
    • Demonstrate any special or complicated procedures and/or equipment.
    • If materials and equipment required are not on their benches, point out their locations or where to find them.
    • Go over any safety guidelines associated with the lab.
    • Provide sufficient instructions for safe use of chemicals and other potentially hazardous laboratory equipment.
  • Throughout the session, ask enough questions to ensure that students understand what is required and they are able to carry out the experiments.

Conducting your lab session

  • Encourage students to work in groups. Limit the group size to three students.
  • Do not sit at the front of the room. Circulate throughout the room and see how the students are doing. As you move from group to group, ask targeted questions to ensure students are learning the key points and understand what they are doing.
  • Try and talk to every individual or group at least once during the session.
  • Take attendance if required. Whether one takes attendance depends on the course policy. Check with the course instructor or SLI in-charge. You can take attendance while you circulate amongst your students.
  • Answer student questions, offer encouragement and useful advice.
  • If you find that students are having difficulties with one part of the experiment, it is advisable you alert the whole class and explain and/or demonstrate the procedure again. If one or two groups are having problems, probably the rest of the class is.

Concluding the Session

  • Ask students to clean their workbenches and put equipment and other supplies in their respective locations if this is required.
  • Reconvene at the end of the class and summarize important findings/conclusions. Explain results that are different than expected. Ask students to offer alternative explanations.
  • Answer any questions students may have.
  • Collect any assignments for marking.
  • End the session on a positive note and remind students of any assignments/tests due during the week or the following week.