Standard Operating Protocols (SOPs)

Standard operating procedures or SOPs are written step-by-step procedures that quality control (QC), quality assurance (QA), and production units use in order to assure the accuracy and precision of the quantitative experimental results and materials that they generate and provide in support of other units such as Research and Development (R&D), manufacturing, etc. SOPs are generally used in support of experimental research whenever there is a need to document the handling of samples, the methods used in their analysis, and the quality of the results generated in the analysis of these samples. SOPs are used by the governmental agencies, private industry, and academic laboratories by scientists and engineers from all of the science, technology, engineering, and mathematical disciplines. Examples of their use include forensic analysis where they are used to establish the chain of custody of evidence and in private biotechnology industry where they are often used to validate new methods of bioanalysis. SOPs can also be extremely valuable in academic laboratories and can be employed anytime there is procedure that potentially more than one person will use in a research group. They can be written to:

  • outline sampling procedures, describe the proper procedures for the transportation of research materials;
  • standardize the methods of training for often used experimental methods and/or analytical instrumentation; and to
  • document the methods used in data handling and/or analysis.

To be effective, SOPs need to describe not only what needs to be, but who is qualified to carry it out, and under what conditions the procedure can be performed reliably.

How do you know if an SOP works? Test it. The best way is to have someone else in the lab unfamiliar with the technique try to follow the SOP to carry out the procedure. SOPs must be reviewed periodically for accuracy and completeness by other scientists who have experience doing the procedure. As such SOPs are invaluable in documenting that the experimental procedure was accomplished properly.

SOPs can be invaluable to students involved in undergraduate research in providing written guidelines detailing how to carry out new/unfamiliar methods reliably. The action of authoring an SOP can be beneficial in helping you to think through the procedures you use in a thoughtful step-by-step manner and document clearly and succinctly in writing your understanding. Thus, the SOP saves you, the author, and those using the SOP precious time and effort since it lays out exactly what must be done in order to achieve the desired results and it provides a timeless means of sharing that information with all who may need it both now and in the near future. Authoring SOPs provides undergraduate students an opportunity to document and showcase their understanding of the methods used in their research and of the quality of their written communication skills.

Example SOP

The following are the main sections you will find in most SOPs together with a brief description of the content of each suggested section. Note that not every SOP will have each of these sections. However, in general, the more information provided, the better the quality of the SOP and the more generally effective the protocol will be in the laboratory.

  1. Title – a clear, succinct title describing the purpose of the SOP and the conditions under which it can be reliably used.
  2. Date – date (including year) of authorship of the current SOP. If the SOP has been revised then a “Date of Revision” and the “Revision Number” should also be included here.
  3. Name of the Author of the SOP – self explanatory
  4. Purpose – Brief explanation of the purpose of this SOP
  5. Scope and Applicability – under what specific conditions can this protocol be used reliably; are there any known interferents or other limitations on the protocol’s effective use?
  6. Introduction – relevant background information on the system, methods, and instruments used.
  7. References - any relevant references to the peer-reviewed literature
  8. Materials and Supplies – list of any reagents including names of suppliers used in this procedure. If the suppliers are obscure sources, a list of addresses and contact information should be provided as well.
  9. Analytical Instrumentation – list of any analytical instruments including manufacturer and model numbers that have been used in this procedure.
  10. Cautions – are there any specific health and safety precautions that should be considered. For example, should gloves be worn? If so, what kind? How should spills, if they occur, be cleaned up? Are there any special procedures that should be followed in order to safely dispose of waste?
  11. Personnel Qualifications – what if anything must the user know or be able to do before being able to carry out this protocol, i.e., is any prior training required and if so what specific kind/form of training?
  12. Names of SOP Reviewers - names of those individuals who have reviewed and approved the SOP for use in the laboratory. Signatures and dates should be provided whenever possible as well.
  13. Actual Protocol – step-by-step set of instructions for accomplishing the procedure of interest reliably. If calculations are involved in analyzing the data, then an example of the calculation should be provided. Figures and tables showing laboratory apparatus, representative data, etc. can be included here.

You will find an example of an SOP here.

Example SOP

TITLE: Preparation of the Perfect Cup of Coffee by the Drip Method
Date of Preparation:


Date of Revision: N/A

Revision No.: N/A

Submitted by: Ay Dot Student

Approved by: Professor Ex

Purpose:Provide an example of a standard operating protocol or SOP that can be appreciated by undergraduate research students from all academic disciplines.

Scope and Applicability: The following protocol can be used wherever quality coffee beans, good drinking water, and a drip coffee maker are available.

Introduction: Coffee is the beverage of choice of many college students. Properly prepared the beverage provides an invigorating and revitalizing effect. One of the most frequently used methods of preparation is the drip method. In this method, water, heated to near boiling temperatures, is slowly added to finely ground coffee beans held in a filter unit. The coffee beverage is collected below the filter unit in a glass carafe. Today this procedure is frequently accomplished using a semi-automated process in an electronic coffee maker. The procedure below outlines a reliable method for preparing drip coffee using any commercially available drip coffee maker, high quality ground coffee beans, and filtered water.

References: For information on coffee beans, the standard methods of preparation of coffee, and recipes see:

Materials and Supplies: Freshly ground Starbucks® coffee (any flavor you prefer; medium grind works best with most commercial coffee makers), commercial 4-c drip coffee maker including filter (gold mesh preferred but high quality paper filter may be used), good quality drinking water (Polar Springs®, Brita®-filtered, or similar quality source recommended), coffee cup, and additives (as desired: sugar or sugar alterative, cream or milk).

Cautions: Hot coffee can scald and burn. Water is an electrical conductor. If spills occur during the brewing process, wait until the brewing process is complete, turn of the electricity, and disconnect the unit from the electricity before attempting to clean up any spills. Accidental spills may be cleaned up with a kitchen sponge and dish washing detergent such as Dawn®, Dove®, or Ajax®. Used coffee grounds can be disposed of in the regular trash. Be sure to carefully read the directions that accompanied your coffee maker unit before attempting to use it. In particular, it is important to find out if your unit has (1) a pause feature that will allow you to remove the carafe while the coffee is brewing; and (2) an auto-off feature that turns off the heater unit located beneath the carafe at a set time after the coffee has been brewed.

Personnel Qualifications: No special knowledge or training is required to make coffee. However, due to the potential risk of burns, it is recommended that anyone performing this procedure who is less than ten years old be actively supervised by an adult.


1. Make sure that the coffee maker is off. Locate water reservoir unit on coffee maker and carefully add 4-cups of clean drinking water to the reservoir. Note that the outside or inside of most quality coffee makers’ water reservoir units are marked for the user’s convenience.

2. Locate the coffee filter assembly on the coffee unit. If you are preparing the standard 4-c carafe of coffee, carefully measure one coffee measure of ground coffee into your units coffee filter assembly. Note that one standard coffee measure is equivalent to 1/8-c of coffee. Close the coffee filter assembly.

3. Plug in the coffee maker and turn the unit on. Wait until the carafe located beneath the coffee filter unit is filled with coffee. Note that some units may have a “pause” feature that will allow you to temporarily remove the carafe and pour a cup of coffee while the unit is working. If you are unfamiliar with your unit, be sure to wait until the unit is done filtering before attempting to remove the carafe.

4. If coffee spills beneath the base of the carafe unit, be sure to turn off the unit and disconnect the electricity before attempting to clean up the spill.

5. Pour yourself a cup of coffee. Most coffee units will keep the carafe warm for a set period of time before turning off automatically. Some however, do not turn off automatically. Be sure to read your coffee maker’s instructions beforehand. If in doubt, be sure to turn off the electricity to your unit after the brewing process is complete.