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Can have and understand book Restriction and Saturation Linguistic Inquiry Monographs sharks of this wave to popularize groups with them. One advantage of the oral presentation, however, is that it provides an opportunity for more direct contact with your audience than does a paper; thus the opportunity exists for immediate questions and feedback. Presentations usually range from 15 to 60 minutes. Shorter presentations cover a much smaller unit of a research project, whereas minute talks often called seminars can give a broader exposure to the research area.
Scientific presentations involve mixed mediaoral and visual. The important verbal points are reinforced with the use of a visual aid such as a figure, graph, or other element. Scientific presenters today most often use PowerPoint, computer software that projects electronic slides onto a screen, although overhead transparencies are also acceptable and efficient. Whatever the type of visual aid, the slides must be carefully constructed with special concern for the total number of slides and the amount of information on each. Some presenters use the approximate ratio of one-to-two slides per minute of presentation.
If your instructor expects you to present a talk, he or she will provide specific information regarding length of time, range of topic, type of visual aids, multimedia, etc. The scientific poster is a communication method that may be considered a hybrid, as it combines elements of the oral presentation verbal expression and visual aids with elements of a paper printed text and figures.
The poster has become the primary medium by which new scientific information is exchanged at all professional conferences, including local, regional, national, and international meetings. The poster, however, may be available to readers for long periods of time in the absence of the presenter.
Some of the specific characteristics that describe a poster include Figure 1. Only the main points such as the purpose, results, conclusions, and future experiments for the project should be included in this concise summary. As a presenter, during your official time at the poster you will be visited by individuals or small groups who will spend an average of about minutes at your poster. Your instructor may request that you prepare a poster for local display at your institution or for presentation at a regional or national meeting.
Specific details will not be given here, as all organizations sponsoring poster sessions at meetings publish their own rules and regulations regarding poster size, font sizes, etc. Many colleges and universities now schedule local meetings where students may obtain experience preparing and presenting posters about their research results. Attend one of these local meetings or walk around the halls of your chemistry and biology departments looking for posters made by research students at your institution. These may serve as very good models for your own creation.
You may also find useful information about the specific details of poster construction by searching the Internet. Some helpful Web sites with poster templates are listed in the Further Reading section at the end of this chapter. Applications of water usage include: 1 solvent for preparing most buffer and reagent solutions; 2 column chromatography; 3 high-performance liquid chromatography; 4 tissue culture; and 5 washing glassware. Both the quality and quantity of water required must be considered for each lab application. Ordinary tap water is relatively abundant, but its quality is very low.
It contains a variety of impurities including particulate matter sand, silt, etc. In addition, the natural degradation of microorganisms leads to the presence of byproducts called pyrogens. Tap water should never be used for the preparation of reagent solutions or for any sensitive procedures. For most laboratory procedures, it is recommended that some form of purified water be used.
The purity of water is usually measured in terms of resistivity the ability of a liquid to restrict the flow of an electric current. Units for resistivity are Megohms cm M. There are five basic water purification technologiesdistillation, ionexchange, activated carbon adsorption, reverse osmosis, and membrane filtration.
Most academic and industrial research laboratories are equipped with in-house purified water, which typically is produced by a combination of the above purifying processes and piped throughout all the labs in a building.
The water quality necessary will depend on the solutions to be prepared and on the biochemical procedures to be investigated. For most procedures carried out in the biochemistry lab, water purified by ion-exchange, reverse osmosis, or distillation is usually acceptable. Of these three processes, distillation is the slowest, least energyefficient, least pure best is 1. Distilled water must also be stored to prevent contamination by microbes. For special procedures such as. Water that is purified only by ion-exchange will be low in metal-ion concentration, but may contain certain organics that are washed from the ion-exchange resin.
These contaminants will increase the UV-absorbance properties of water. If sensitive UV-spectroscopic measurements are to be made, distilled water especially glassdistilled is better than de-ionized. If large volumes of high-purity water are required Cleaning Laboratory Glassware The results of your experimental work will depend, to a great extent, on the cleanliness of your equipment, especially glassware used for preparing and transferring solutions.
There are at least two important reasons for this: 1 many of the chemicals and biochemicals will be used in milligram, microgram, or even nanogram amounts. Any contamination, whether on the inner walls of a beaker, in a pipet, or in a glass cuvette, could be a significant percentage of the total experimental sample; 2 many biochemicals and biochemical processes are sensitive to one or more of the following common contaminants: metal ions, detergents, and organic residues.
In fact, the objective of many experiments is to investigate the effect of a metal ion, organic molecule, or other chemical agent on a biochemical process. Contaminated glassware will virtually ensure failure in these activities. The preferred method for cleaning glassware is to begin with hot tap water.
Rinse the glassware at least 10 times with this; then rinse 46 times with distilled or de-ionized water. Occasionally it is necessary to use a detergent for cleaning. Use a dilute detergent solution 0. Dry equipment is required for most processes carried out in the biochemistry laboratory. When you needed dry glassware in the organic laboratory, you probably rinsed the glassware with acetone, which rapidly evaporated, leaving a dry surface.
Unfortunately, this technique coats the surface with an organic residue consisting of nonvolatile contaminants found in the acetone. Because this residue could interfere with your experiments, it is best to refrain from acetone washing. Glassware and plasticware should be rinsed well with purified water and dried in an oven designated for glassware, not one used for drying chemicals. Never clean cuvettes or any optically polished glassware with ethanolic KOH or other strong base, as this will cause etching. All glass cuvettes should be cleaned carefully with hot tap water or 0.
Solutions: Concentrations and Calculations The concentrations for solutions used in the biochemistry laboratory may be expressed in several different units. The most common units are: Molarity M : concentration based on the number of moles of solute per liter of solution. In biochemistry, it is more common to use concentration ranges that are. A 1 mM solution of alanine contains 0.
How many grams of alanine are present in mL of the 1 mM alanine solution? Ans: 0. How many milligrams of alanine are present in mL? Ans: 8. How many grams of alanine are present in 10 g of this solution? Many solutions you use will be based on molarity. For practice, assume you require 1 liter of solution that is 0. Add about mL of purified water and swirl to dissolve. Then add water so that the bottom of the meniscus is at the etched line on the flask. Stopper and mix well. The flask must be labeled with solution contents 0.
Assume that you need only mL of 0. Explain how you would prepare the solution.
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Emphasize any changes from Part a. For example, you may need to know the concentration of the 0. Here are some basic calculations for practice. Convert the concentration units of 0. According to the procedure described in Study Exercise 1. This is equivalent to 1. Therefore, the 0. Calculate the concentration of a 0. The density of ethanol is 0. How many grams of alanine are present in 50 mL of this solution? Ans: 5 g. How many grams of alanine would be present in 2 liters of this solution?
In 10 mL? Ans: 10 g; 0. Preparing and Storing Solutions In general, solid solutes should be weighed on weighing paper or plastic weighing boats, with the use of an electronic analytical or top-loading balance. Liquids are more conveniently dispensed by volumetric techniques; however, this assumes that the density is known. If a small amount of a liquid is to be weighed, it should be added to a tared flask by means of a disposable Pasteur pipet with a latex bulb. The hazardous properties of all materials should be known before use read MSDS and the proper safety precautions obeyed.
The storage conditions of reagents and solutions in the biochemistry lab are especially critical. Although some will remain stable indefinitely at room temperature, it is good practice to store all solutions in a closed container. Often it is necessary to store some solutions in a refrigerator at 4C. This inhibits bacterial growth and slows decomposition of the reagents. Some solutions may require storage below 0C. If these are aqueous solutions or others that will freeze, be sure there is room for expansion inside the container.
Stored solutions must always have a label containing the name and concentration of the solution, the date prepared, and the name of the preparer. All stored containers, whether at room temperature, 4C, or below freezing, must be properly sealed. This reduces contamination by bacteria and vapors in the laboratory air carbon dioxide, ammonia, HCl, etc.
Volumetric flasks, of course, have glass stoppers, but test tubes, Erlenmeyer flasks, bottles, and other containers should be sealed with screw caps, corks, or hydrocarbon foil Parafilm. Remember that hydrocarbon foil, a wax, is dissolved by solutions containing nonpolar organic solvents like chloroform, diethyl ether, and acetone.
Bottles of pure chemicals and reagents should also be properly stored. Many manufacturers now include the best storage conditions for a reagent on the label. The common conditions are: store at room temperature; store at 04C; store below 0C; or store in a desiccator at room temperature, 04C, or below 0C.
Many biochemical reagents form hydrates by taking up moisture from the air. If the water content of a reagent increases, the molecular weight and purity of the reagent change. The actual molecular weight that should be used for solution preparation is However, if this reagent is stored in a moist refrigerator or freezer outside a desiccator, the moisture content may increase to an unknown value.
Many analytical techniques must be mastered, but few are as important as the quantitative transfer of solutions. Some type of pipet will almost always be used in liquid transfer. Because students may not be familiar with the many types of pipets and the proper techniques in pipetting, this instruction is included here. Pipets and Pipetting Pipet Fillers. The use of any pipet requires some means of drawing reagent into the pipet. Liquids should never be drawn into a pipet by mouth suction on the end of the pipet!
Small latex bulbs are available for use with disposable pipets see Figure 1. For volumetric and graduated pipets, two types of bulbs are available. One type see Figure 1. To use these, first place the pipet tip below the surface of the liquid. Squeeze the bulb with the left hand if you are a right-handed pipettor and then hold it tightly to the end of the pipet. Slowly release the pressure on the bulb to allow liquid to rise to 2 or 3 cm above the top graduated mark. Then, remove the bulb and. The level of solution in the pipet will fall slightly, but should not fall below the top graduated mark.
If it does fall too low, use the bulb to refill. Safety Pipet Fillers. Mechanical pipet fillers made of silicone and sometimes called safety pipet fillers, propipets, or pi-fillers are more convenient than latex bulbs. As shown in Figure 1. The use of a safety pipet filler is outlined in Figure 1.
Never allow any solvent or solution to enter the pipet bulb! To avoid this, two things must be kept in mind: 1. Always maintain careful control while using valve S to fill the pipet. Never use valve S unless the pipet tip is below the surface of the liquid. If the tip moves above the surface of the liquid, air will be sucked into the pipet and solution will be flushed into the bulb. Disposable Pasteur Pipets. Often it is necessary to perform a semi-quantitative transfer of a small volume mL of liquid from one vessel to another.
Because pouring is not efficient, a Pasteur pipet with a small latex bulb may be used see Figure 1. Pasteur pipets are available in two lengths 15 and 23 cm and hold about 2 mL of solution. These are especially convenient for the transfer of nongraduated amounts to and from test tubes.
If dilution is not a problem, rinsing the original vessel with a solvent will increase the transfer yield. Used disposable pipets should be discarded in special containers for broken glass. Calibrated Pipets. Although most quantitative transfers are now done with automatic pipetting devices, which are described later in the chapter, instructions will be given for the use of all types of pipets. If a quantitative transfer of a specific and accurate volume of liquid is required, some form of calibrated pipet must be used.
Volumetric pipets see Figure 1. To use these pipets, draw liquid with a latex bulb or mechanical pipet filler to a level 23 cm above the fill line. Release liquid from the pipet until the bottom of the meniscus is directly on the fill line.
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Touch the tip of the pipet to the inside of the glass wall of the container from which it was filled. Transfer the pipet to the inside of the second container and release the liquid. Hold the pipet vertically, allow the solution to drain until the flow stops, and then wait an additional seconds. Touch the tip of the pipet to the inside of the container to release the last drop from the outside of the tip. Remove the pipet from the container. Some liquid may still remain in the tip.
Most volumetric pipets are calibrated as TD to deliver , which. Using thumb and forefinger, press on valve A and squeeze bulb with other fingers to produce a vacuum for aspiration. Release valve A, leaving bulb compressed. To deliver the last drop, maintain pressure on valve E, cover E inlet with middle finger, and squeeze the small bulb. Fractional volumes of liquid are transferred with graduated pipets, which are available in two types: Mohr pipets see Figure 1.
Long-tip pipets are especially attractive for transfer to and from vessels. Virtually all Mohr pipets are TD, and they are available in many sizes 0. The marked subdivisions are usually 0. Selection of the proper size is especially important. For instance, do not try to transfer 0. Use the smallest pipet that is practical. The use of a Mohr pipet is similar to that of a volumetric pipet. Draw the liquid into the pipet with a pipet filler to a level about 2 cm above the 0 mark. Lower the liquid level to the 0 mark.
Remove the last drop from the tip by touching it to the inside of the glass container. Transfer the pipet to the receiving container and release the desired amount of solution. The solution should not be allowed to move below the last graduated mark on the pipet. Touch off the last drop. Serological pipets see Figure 1. Their use is identical to that of a Mohr pipet except that the last bit of solution remaining in the tip must be forced out into the receiving container with a rubber bulb.
This final blow-out should be done after seconds of draining. Cleaning and Drying Pipets.
Special procedures are required for cleaning glass pipets. Immediately after use, every pipet should be placed, tip up, in a vertical cylinder containing warm tap water or a dilute detergent solution less than 0. The pipet must be completely covered with solution. This ensures that any reagent remaining in the pipet is forced out through the tip. If reagent solutions are allowed to dry inside a pipet, the tips can easily become clogged and are very difficult to open.
After several pipets have accumulated in the water or detergent solution, the pipets should be transferred to a pipet rinser. Pipet rinsers continually cycle fresh water through the pipets. Immediately after detergent wash, tap water may be used to rinse the pipets, but distilled water should be used for the final rinse. Pipets may then be dried in an oven. Automatic Pipetting Devices For most quantitative transfers, including many repeated small-volume transfers, a mechanical microliter pipettor i.
This allows accurate, precise, and rapid dispensing of fixed volumes from 1 to 10, mL 0. The pipets push-button system can be operated with one hand, and it is fitted with detachable polypropylene tips see Figure 1. The advantage of polypropylene tips is that the amount of reagent film remaining in the pipet after delivery is much less than for glass tips. Mechanical pipettors are available in many different sizes. Newer models offer continuous volume adjustment, so a single model can be used for delivery of specific volumes within a certain range. Multichannel pipettors are available, which fill several containers or wells at once see Figure 1.
Set the desired volume with the digital micrometer or plunger button. Attach a new disposable tip to the shaft of the pipet. Press tip on firmly with a slight twisting motion. Depress the plunger to the first positive stop, immerse the disposable tip into the sample liquid to a depth of 24 mm, and allow the pushbutton to return slowly to the up position and wait 12 seconds. To dispense sample, place the tip end against the side wall of the receiving vessel and depress the plunger slowly to the first stop.
Wait 23 seconds, and then depress the plunger to the second stop to achieve final blow-out. Withdraw the device from the vessel carefully with the tip sliding along the inside wall of the vessel. Allow the plunger to return to the up position. Discard the tip by depressing the tip ejector button.
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Photos courtesy of Rainin Instrument Company, Inc. Pipetman is a registered trademark of Gilson Medical Electronics. Exclusive license to Rainin Instrument Company, Inc. To use the pipettor, choose the proper size and place a polypropylene pipet tip firmly onto the cone, as shown in Figure 1. Tips for pipets are available in several sizes, for , , , , and 10,mL capacities. Details of the operation of an adjustable pipet are shown in Figure 1. For rapid and accurate transfer of volumes greater than 5 mL, automatic repetitive dispensers are commercially available.
These are particularly useful for the transfer of corrosive materials. The dispensers, which are available in several sizes, are simple to use. The volume of liquid to be dispensed is mechanically set; the syringe plunger is lifted for filling and pressed downward for dispensing. Hold the receiving container under the spout while depressing the plunger. Touch off the last drop on the inside wall of the receiving container. PipetLite is a registered trademark of Rainin Instrument Company. The characteristic is often quantitativea single number or a group of numbers.
These measured quantities may be the molecular weight of a protein, the pH of a buffer solution, the absorbance of a colored solution, the rate of an enzyme-catalyzed reaction, the concentration of a protein in solution, or the radioactivity associated with a molecule. If you measure a quantitative characteristic many times under identical conditions, a slightly different result will most likely be obtained each time. For example, if a radioactive sample is counted twice under identical experimental and instrumental conditions, the second measurement immediately following the first, the probability is very low that the numbers of counts will be identical.
If the absorbance of a solution is determined several times at a specific wavelength, the value of each measurement will surely vary from the others. If an assay for cholesterol is performed several times on a blood serum sample from the same individual, the values will probably be close, but not all will be the same see Study Problem 1. Which measurements, if any, are correct? Before this question can be answered, you must understand the source and treatment of numerical variations in experimental measurements.
Defining Statistical Analysis An error in an experimental measurement is defined as a deviation of an observed value from the true value. There are two types of errors, determinate and indeterminate. Determinate errors are those that can be controlled by the. These are sometimes called human errors because they can be corrected or at least partially alleviated by careful design and performance of the experiment.
Indeterminate errors are those that are random and cannot be controlled by the experimenter. Specific examples of indeterminate errors are variations in radioactive counting and small differences in the successive measurements of glucose in a serum sample. Two statistical terms involving error analysis that are often used and misused are accuracy and precision. Precision refers to the extent of agreement among repeated measurements of an experimental value.
Accuracy is defined as the difference between the experimental value and the true value for the quantity. Because the true value is seldom known, accuracy is better defined as the difference between the experimental value and the accepted true value. Several experimental measurements may be precise that is, in close agreement with each other without being accurate.
If an infinite number of identical, quantitative measurements could be made on a biosystem, this series of numerical values would constitute a statistical population. The average of all of these numbers would be the true value of the measurement. It is obviously not possible to achieve this in practice. The alternative is to obtain a relatively small sample of data, which is a subset of the infinite population data.
The significance and precision of these data are then determined by statistical analysis. Most quantitative biological measurements can be made in duplicate, triplicate, or even quadruplicate, but it would be impractical and probably a waste of time and materials to make numerous determinations of the same measurement. Rather, when you perform an experimental measurement in the laboratory, you will collect a small sample of data from the population of infinite values for that measurement.
To illustrate, imagine that an infinite number of experimental measurements of the pH of a buffer solution are made, and the results are written on slips of paper and placed in a container. It is not feasible to calculate an average value of the pH from all of these numbers, but it is possible to draw five slips of paper, record these numbers, and calculate an average pH.
By doing this, you have collected a sample of data. By proper statistical manipulation of this small sample, it is possible to determine whether it is representative of the total population and the amount of confidence you should have in these numbers. It is impossible to predict with certainty when a radioactive event will occur. Therefore, a series of measurements made on a radioactive sample will result in a series of different count rates, but they will be centered around an average or mean value of counts per minute.
Table 1. A similar table could be prepared for other biochemical measurements, including the rate of an. The arithmetic average, or mean, of the numbers is calculated by totaling all the experimental values observed for a sample the counting rates, the velocity of the reaction, or protein concentration and dividing the total by the number of times the measurement was made. The mean is defined by Equation 1. If the same radioactive sample were again counted for a series of ten observations, that series of counts would most likely be different from those listed in the table, and a different mean would be obtained.
If we were able to make an infinite number of counts on the radioactive sample, then a true mean could be calculated. The true mean would be the actual amount of radioactivity in the sample. Although it would be desirable, it is not possible experimentally to measure the true mean. Therefore, it is necessary to use the average of the counts as an approximation of the true mean. Because it is not usually practical to observe and record a measurement many times as in Table 1. This may be stated in the form of a question. How close is the result to the true value? One approach to this analysis is to calculate the sample deviation, which is defined as the difference between the value for an observation and the mean value, x Equation 1.
The sample deviations are also listed for each count in Table 1. A more useful statistical term for error analysis is standard deviation, a measure of the spread of the observed values.
Standard deviation, s, for a sample of data consisting of n observations may be estimated by Equation 1. It is a useful indicator of the probable error of a measurement. Standard deviation is often transformed to standard deviation of the mean or standard error. This is defined by Equation 1. It should be clear from this equation that as the number of experimental observations becomes larger, sm becomes smaller, or the precision of a measurement is improved.
Standard deviation may also be illustrated in graphical form see Figure 1. The shape of the curve in Figure 1. This mathematical. The value of x is measured at the maximum height of the curve. The normal distribution curve shown in Figure 1. By using an equation derived by Gauss, it can be calculated that for a single set of sample data, Stated in other terms, there is a For many experiments, a single measurement is made, so a mean value, x, is not known.
The parameter k is a proportional constant between Ex and the standard deviation. The percent proportional error may be defined within several probability ranges. Standard error refers to a confidence level of The constant k then becomes 1. The previous discussion of standard deviation and related statistical analysis placed emphasis on estimating the reliability or precision of experimentally observed values.
However, standard deviation does not give specific information about how close an experimental mean is to the true mean. Statistical analysis may be used to estimate, within a given probability, a range within which the true value might fall. The range or confidence interval is defined by the experimental mean and the standard deviation.
This simple statistical operation provides the means to determine quantitatively how close the experimentally determined mean is to the true mean. Confidence limits L1 and L2 are created for the sample mean as shown in Equations 1. Values of t are tabulated for various confidence limits Table 1. Each column in the table refers to a desired confidence level 0.
The values of x and sm are calculated as previously described in Equations 1. TABLE 1. Spreadsheet Statistics It is common practice today to use computer spreadsheet programs for statistical analysis of biochemical data. A spreadsheet provides a means to collect and enter data in the form of numbers and text. Perhaps the most versatile and easy-to-use spreadsheet software is Microsoft Excel, although more specialized statistical software programs including SPSS and SyStat are also very useful see Chapter 2 and Appendix I.
Using Excel to estimate statistical terms for experimental data is relatively straightforward. Launching the Microsoft Excel program on your computer brings up the Excel spreadsheet, which consists of rows number headings and columns letter headings. More detailed instructions for the statistical applications of Excel are found at www. Statistical Analysis in Practice The equations for statistical analysis that have been introduced in this section are of little value if you have no understanding of their practical use, meaning, and limitations.
A set of experimental data will first be presented, and then several statistical parameters will be calculated using the equations. This example will serve as a summary of the statistical formulas and will also illustrate their application. The following values for protein concentration were obtained. Calculation of the sample deviation for each measurement gives an indication of the precision of the determinations. The mean can now be expressed as x ; s for this specific example, 1. The probability of a single measurement falling within these limits is For Therefore, we will choose a value for t from Table 1.
Study Problems 1.
What personal protection items must be worn when handling glacial acetic acid? Define each of the following terms. Draw a schematic picture of your biochemistry lab and mark locations of the following safety features: eyewashes, first-aid kit, shower, fire extinguisher, chemical-spill kits, and direction to nearest exit. Chapter 1 Introduction to the Biochemistry Laboratory 4. Describe how you would prepare a 1-liter aqueous solution of each of the following reagents: a 1 M glycine b 0. Why is de-ionized ion-exchange water not suitable as a solvent for use in UV absorbance measurements?
Clinical Biochemistry, Volume 1: Contemporary Theories & Techniques
Describe how you would prepare just 10 mL of each of the solutions in Problem 4. If you mix 1 mL of the 1 M glycine solution in Problem 4a with 9 mL of water, what is the final concentration of this diluted solution in mM? You have just prepared a solution by weighing 20 g of sucrose, transferring it to a 1-liter volumetric flask, and adding water to the line. These are standard concentration units used in the clinical chemistry lab. Convert the concentrations to mM.
The following optical rotation readings were taken by a polarimeter on a solution of an unknown carbohydrate. Use Excel or other statistical software to estimate statistical terms. Describe how you would prepare mL of a single solution containing all of the following reagents at the designated concentrations. How would you prepare 1 liter of a 1 M ethanol solution in water? You do not have an analytical balance available, only a 1-liter volumetric flask and a mL graduated cylinder.
A technician at a clinical laboratory received a blood serum sample for cholesterol analysis. In order to check the reliability of the procedure, the technician repeated the assay five times and obtained the results below. Use a spreadsheet statistical analysis to estimate the mean, standard deviation, variance, and standard error of the mean for the data. Caspers and E. Roberts-Kirchhoff, Biochem. Kegley and J. A discussion of water purity and analysis.
Risley, J. Preparing Solutions in the Biochemistry Lab. Alaimo, Handbook of Chemical Health and Safety, 1st ed. Chapter 1 Introduction to the Biochemistry Laboratory www. Boyer, Modern Experimental Biochemistry, 3rd ed. Meier and R. Garland Science. Powell, Sept. Amsler, Mark University of Delaware Press. Astbury, W. Bibcode : Natur. Ben-Menahem, Ari Historical Encyclopedia of Natural and Mathematical Sciences. Berlin: Springer. Bibcode : henm.
Burton, Feldman Arcade Publishing. Butler, John M. Academic Press. Sen, Chandan K. DNA and Cell Biology. Clarence, Peter Berg Edwards, Karen J. Journal of Molecular Biology. Eldra P. Solomon; Linda R. Berg; Diana W. Martin Biology, 8th Edition, International Student Edition. Archived from the original on Fariselli, P. Briefings in Bioinformatics. Fiske, John Boston and New York: Houghton, Mifflin. Retrieved 16 February Lippincott's Illustrated Reviews: Pharmacology 4th ed. Krebs, Jocelyn E. Essential Genes.
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The Chemical Educator. Knowles, J. Annual Review of Biochemistry. Miller G; Spoolman Scott Cengage Learning. Retrieved Nielsen, Forrest H. Maurice E. Shils; et al. Ultratrace minerals; Modern nutrition in health and disease. Peet, Alisa Marks, Allan; Lieberman Michael A. Rayner-Canham, Marelene F. Chemical Heritage Foundation. Rojas-Ruiz, Fernando A. Saenger, Wolfram Principles of Nucleic Acid Structure.
New York: Springer-Verlag. Slabaugh, Michael R. Organic and Biochemistry for Today 6th ed. Pacific Grove: Brooks Cole. Animal Physiology: From Genes to Organisms. Biochemistry 6th ed. San Francisco: W. Tropp, Burton E. Molecular Biology 4th ed. Facts for life PDF 4th ed. Essentials of glycobiology. Cold Spring Harbor Laboratory Press. Voet, D; Voet, JG Biochemistry 3rd ed. Archived from the original on September 11, Whiting, G. C Hulme ed. The Biochemistry of Fruits and their Products.
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