Prepared by
Nam Sun Wang
Department of Chemical & Biomolecular Engineering
University of Maryland
College Park, MD 20742-2111

Table of Contents

Satisfactory performance of this laboratory course work in biochemical engineering requires that the student has had experience in freshman chemistry or physics laboratories. In addition, familiarity in biochemical engineering at the introductory level is assumed. The student should have taken or is concurrently enrolled in an introductory undergraduate course in biochemical engineering. Because this is essentially a senior elective course offered by the chemical engineering department, the student should be able to apply meaningfully what one has learned from the previous fundamental courses in transport, kinetics, thermodynamics, and engineering mathematics.

Course Format

Immediately preceeding each experiment, there will be a short lecture ranging between 10 to 45 minutes, depending on the subject. This introductory lecture will briefly cover the background principles, caution avoidable pitfalls, answer any questions that may rise, and demonstrate techniques that have not been explicitly discussed in the instruction manual. Any questions may be directed at any time to the instructor or Mr. Jiefei Huang, our Teaching Assistant for this semester. The laboratory itself will be closely supervised by the T.A. It is the T.A.'s responsibility to perform the entire experimental procedures at least once before the class to ensure that all the necessary equipment and supplies are available for the smooth operation of each experiment. The T.A. should be thoroughly familiar with the instructions. Conducting a trial run is a key to the success of a laboratory course because there are always many components that can be overlooked.

Minimum Class Performance

As with any other laboratory course, it is imperative that the student prepares for each experiment beforehand. I can promise that the amount of time and effort spent on preparation shall reflect on the student's work and, ultimately, my evaluation of the student's performance. The student is to read not only the instructions but also comprehend all the procedures and concepts prior to coming to the class. This is to be achieved by requiring that the objectives and procedures for that experiment be clearly stated in the student's bound, paged notebook in his own words before coming to the class. The student is encouraged to raise questions during the introductory lecture if additional explanation or clarification of laboratory procedures is required. Otherwise, the student is assumed to understand the material thoroughly. Because various chemicals and equipment can be potentially dangerous if not used correctly, laboratory admission will not be granted to those who are unsure of what needs to be carried out. Furthermore, because most of the critical biochemicals and enzymes required in this course are relatively expensive and unstable, only a minimal amount will be provided to each student. Very likely, there will not be enough supplies to repeat the experiment if it fails, nor will there be sufficient time for the class is tightly scheduled.

Because this course is offered in a chemical engineering program, analytical aspects of the experiment as well as the conceptual aspect will be emphasized. The thorough analytical treatment of the data will ensure that the engineering aspect will be preserved, whereas the questions at the end of each experiment are designed to enhance the conceptual understanding of the underlying principles of the subject. The student must master the laboratory techniques to yield good results. One must apply the correct analytical methods to reduce the raw laboratory data to a set of more meaningful parameters. Above all, one must understand, not merely memorize, the guiding principles. In summary, this course will not at all emphasize rote memorization, but will encourage creativity in each student. If better procedures can be found, let them be followed.

Laboratory Notebook

Use a bound (not the spiral type) laboratory notebook with pages numbered consecutively at the upper corners. A permanent-ink pen should be used in entering information in the laboratory notebook; no pencils or water-soluble felt-tip pens will be allowed. The student is forewarned that this rule will be enforced by placing his notebooks under running water or by wiping the surface with a wet sponge in class periodically and unannounced. After this deliberate destructive procedure is carried out, the student will be held responsible for the permanent loss of data as a result of using pencils or water-soluble ink; i.e., he may be assigned an "F" for the experiment in which there is a significant loss of data, as if the data were never taken.

In general the laboratory notebook should serve as the quantitative aspect of the course. Procedures, instrumentation, and data should be recorded in such a way that any person could pick up the notebook and conduct the experiment with reproducible results. The typewritten report, on the other hand, should incorporate qualitative analysis as well as insightful interpretations and observations of one's experimental results. This is why one may sometimes find himself doing library research in order to answer fully the questions in the handouts. Remember, good lab techniques go hand in hand with the ability to analyze data meaningfully -- they are equally important.

As mentioned previously, enter the experiment title, the objective, and the procedure in your own words before coming to the class. The notebook will be collected and graded periodically.

Title of the Experiment

This part is self explanatory, simply copy from the instruction manual.


The objectives should be concise and explicitly stated, usually in one sentence.


Write down the steps of the experiment. A graphical representation of the steps outlined in the instruction manual may greatly help the student visualize the experiment. Also note the purpose of the step if it is not totally obvious. It is to be emphasized that the student is not asked to copy the laboratory manual, nor will a mere copying be accepted under any circumstances, for it is universally considered as a form of plagiarism, a serious academic offense punishable by an immediate and automatic dismissal from this class and a possible expulsion from the University of Maryland. The amount of information entered in this section is considered adequate if one can perform the experiment in class without referring back to the original laboratory manual.


The very first entry on the day of the class should be the date. All data taken in the laboratory must be entered directly in the notebook. Data recorded on a loose sheet of paper will be discarded whenever it is found. Once entered, data are never erased from the notebook. Strike out erroneous entries with a continuous, straight line. Also remember to record other pertinent qualitative observations, as well. Convert all data into physical units whenever possible. For example, the content of a colored compound in a solution may be measured in absorbance or transmittance units, but it is the absolute concentration units such as g/l, mole/l, and weight percent that are desired. Graphic results should be affixed permanently in the notebook. In addition, calculations and data analysis needed to reduce the raw data into meaningful results are carried out and recorded directly in the notebook.

Format for the Laboratory Report

A typewritten report is to be submitted promptly a week after each experiment. No handwritten reports or illegible photocopies are accepted. The equations, figures, and tables must also be professionally done. Number all pages of the report; number all equations consecutively. There is absolutely no excuse for misspelled words. Consult a dictionary if there is the slightest doubt about spelling. It is straight forward to run the report through a spelling check program if it is composed on a computer. Furthermore, there is also no excuse for simple grammatical errors such as subject-verb agreement, whether English is one's native tongue or not. The report, as in other aspects of one's work here at the University of Maryland, is expected to be carried out to the best of one's ability. Hurried, sloppy work will not be tolerated. The submitted work should be the repeatedly revised version of the preliminary draft. The regular use of a text editor or a word processor in composing the report on a computer should make the process of revision much less painful.

A major shortcoming in student report writing is that of being too wordy. The goal of any report is to present to the reader the necessary information so that he will understand what was done, why it was done, how it was done, and what was learned, but no more. To do this efficiently is difficult and requires practice. Keep in mind that communication skills, both writing and oral, are just as important as the technical contents; one will not advance very far in his career if no one else is informed of his great discoveries.

All written material must be the student's own work; use one's own words, not someone else's, especially in describing the background or literature survey. Plagiarism will not be tolerated, not even for half a sentence. Plagiarism will be dealt with according to University Regulations. Give proper credit to other people's work if used.

The scope and length of each section are governed by the nature of the subject material. Depending upon the purpose of the report, some of the sections may be emphasized, combined, or even deleted, while others may be added. Use subheadings to divide the report into smaller logical units if necessary. In general, the following format, somewhat complementing that of the instruction manual, is suggested for the laboratory report.

The report shall simply start with the title and the objectives of the experiment, followed by a summary of the results obtained. Discuss the results in, of course, the


section. Finally, answer the questions to the best of one's ability.

Title Page


Simply copy from one's notebook.


This should be a very brief and incisive summary that covers the following:

Materials and Methods

This section is required only for the individual project. However, the student may include this section if the procedures he followed differed significantly from those specified in the instruction manual.


Summarize the data and present any significant experimental findings. Whenever possible, the results should be presented in graphical or tabular forms because they are much easier to comprehend and interpret. The graphs and tables should be accompanied by a verbal description of the results that draws attention to their most noteworthy characteristics. The data should be in the reduced form (e.g. actual physical units rather than voltage readings) in order to interpret them in the most general terms. All of the results of the experiment or theoretical calculation that are to be referred to in the Discussion and Conclusions sections should be presented in this section. The significance of the numbers, the general trends, or the lack of them should be pointed out. Explain any significant or unexpected deviations. Although there should be no surprises in these experiments, the student must be trained to make a careful note of any abnormalities habitually. This is especially important in a research environment, for many great discoveries have been made accidentally. (If the phenomenon is normal and commonplace, someone else must have already observed it.)


Interpret the experimental results in terms of physical and chemical principles and the particular circumstances of the experiment. Indicate the reliability of the reduced experimental data and the sensitivities and uncertainties in the theories. Compare the results with those expected on the basis of theory or empirical correlations, and discuss any discrepancies. State any assumptions explicitly and verify their validity rigorously. Compare the results to what the student expects and to other classmates' whenever possible. State how one's finding differ from others, or how the result depend on the various assumptions.

Mention any nonstandard steps taken to calculate the results and indicate one's confidence level in them. Interpret the results in terms of the underlying physical and chemical principles. State any assumptions explicitly and verify their validity rigorously.

Discuss any alternatives that should be considered. Propose what is to be done next. Since this is the first time that the course is offered in a well organized manner, the student's constructive comments on all aspects of the laboratory will be wholeheartedly welcomed to improve this course for the next year. How can the procedures be changed to achieve better and clearer results? Should the objective be modified? What parts were interesting, and what were boring? What was actually learned, or what did the student wish he could have learned instead? Within the limits of time, budget, availability of equipment, and overall course description, what sort of experiments would the student really like to perform? (Remember that this is a biochemical engineering laboratory; there will not be experiments dealing with bombs made from nitroglycerin.) Although a tentative schedule has been made, by issuing constructive comments, the student can greatly influence the type of experiment he and his classmates will perform and enjoy in the coming weeks.


Briefly summarize the findings supported by the data and the subsequent calculations of this experiment. Describe how the phenomenon investigated depends upon the variables that have been investigated.

Answers to Questions

Attempt to answer all the questions to the best of one's ability before coming to the laboratory class. Direct questions to the instructor or the teaching assistant if help is needed. Hints and pointers will be given liberally; however, the student should not expect them to carry out his work. Note that the answers to some of the questions result from the subsequent analysis of the experimental data obtained in class. Therefore, it is emphasized that the student work them out first as he is writing down the procedures. The student should be fully aware of the additional steps other than the ones explicitly stated in the procedure that one must perform to obtain the required data in the laboratory. Make a note of these hidden steps in the Procedures section because successes in any experiment depend heavily on careful planning. Otherwise, one may later find that he cannot produce a satisfactory report because he has failed to perform certain steps or neglected to record some essential data.

Tables and Figures

Tables and figures must have descriptive titles and must include important details. All tables and figures must be referred to in the text, otherwise there is no need for them in the report. However, the contents of the tables and figures must be clear without having to refer to the report's text. For a figure, for example, a poor title is "Heat-Transfer Coefficient versus Flow Rate. "A better title is "Effect of Water Flow Rate on Overall Heat-Transfer Coefficient in Methanol Condenser at 1 Atm. "Use words as well as letters for labelling axes. Thus, write "Pressure" as well as "P", "Friction Factor" as well as "F",etc. The units should be included in all figures and tables. The same data should only be represented either as a table or as a figure but not both.


One may follow the alphabetical format (sorted according to last names) or numerical format (sorted according to the order of citation in the main text). Use the same format consistently throughout the entire report. See any standard journal articles if the student is not familiar with the standard formats.


Those materials that do not quite fit in the main text should be included in the


section. Each appendix should be a stand alone unit.

Overall Hints

Here are listed some general hints on clear writing styles.

Return to Prof. Nam Sun Wang's Home Page
Return to Biochemical Engineering Laboratory (ENCH485)

Forward comments to:
Nam Sun Wang
Department of Chemical & Biomolecular Engineering
University of Maryland
College Park, MD 20742-2111
301-405-1910 (voice)
301-314-9126 (FAX)