Dilutions of solutions introduction to chemistry lumen learning. Start studying microbiology lab enumeration of bacteria, serial dilution, maconkey agar, mannitol salt agar, effect of uv light. A 25 ml volumetric pipette was used to transfer a 25. Serial dilution plating involves assaying the number of cells in the liquid medium that can form viable colonies on solid culture, a measurement known as the cultures colonyforming units. Before doing plate counts, serial dilutions are required. As shown in the illustration below, it begins when 1 ml of the bacterial sample is added to 9 ml, and it is mixed together creating a 101 dilution. Upon completion of this lab, the student should be able to proficiently calculate molarities for solutions. The concentration of bacteria in this tube is 1100 of the original sample. They are described as ratios of the initial and final concentrations. Booker microbiology 2310 lab report 3 serial dilutions october 15, 2017 introduction. Using a new pipette, 1 ml from the 10 1 dilution tube is transferred aseptically to the 102 dilution tube.
A serial dilution is a series of simple dilutions which amplifies the dilution factor quickly. Each successive solution is diluted so that the concentration of solute is changed by a desired ratio. Lab math solutions, dilutions, concentrations and molarity. However, the numbers of microbes in a given specimen are required to identify in particular aspect such as diary manufacturing, diseases research and study, and. The ability to determine with any reliability the numbers of viable organisms growing on the plates was not achieved in this experiment. For example, in tenfold serial dilutions each successive dilution is one tenth of the previous dilution yielding dilution ratios of 110, 1100, 1, and so on. For serial dilution method, increase dilution of sample will decrease the colony count on the agar plate. The organization, accuracy, completeness, interest in topic, results and. The power point can be used to reveal instructions to the students during the lab. The dilution error although present in the serial dilution experiment is not an. The userfriendly software andrew lab, combined with the pipetting robot andrew, simplifies volume calculation and the design of the experiment. Prepare replicates of this optimal dilution and repeat the a 595 measurement.
Complete lab report for experiment 1 of the applied microbiology lab work. Better at teaching this than my actual lab professor. Calculate the mass of sucrose needed to prepare 200 ml of 1. Be sure to include all details of this calculation in your report. A serial dilution is the stepwise dilution of a substance in solution. We get the result by using serial dilution, spread plate method and gram staining.
The format of the report is that of a journal submission. C serial dilution of unknown to find proper dilution that gives a 595 values between 0. After labeling 5 beakers ad and a stock of 30 ml of the dye solution, 10 ml of the stock solution plus 10 ml of water was transferred into beaker a. This is the correct result from the experiment and correct format for the lab report. A serial dilution is the dilution of a sample, in 10fold dilutions. To verify this conclusion, the first experiment varying the number of mix. A dilution in chemistry is a process that reduces the concentration of a substance in a solution. Microbiology lab enumeration of bacteria, serial dilution.
As such, microbiologists have employed serial dilution and various plating. Unknown assignment report, due june 8th change of date is worth about 33% of your lab grade, more than all the practicums combined. A serial dilution is the repeated dilution of a solution to amplify the dilution factor quickly. Serial dilution is a method intended to reduce the numbers of colonies to a range between 30 and 300. Often, a worker will need to change the concentration of a solution by changing the amount of solvent. Be careful to not crash the objective into the hemocytometer at the time of focusing. Serial dilutions are often performed in steps of 10 or 100. A microbe is an organism that is microscopic and submicroscopic, which is too tiny to be viewed under a naked eye. If the technique is done correctly, then the living viable cells will be counted as a colony forming unit cfu that will decrease following the increasing of total dilution and the original sample cell could be calculated based on the result. You had physically diluted the culture by 106 at this point in your dilution scheme. Introduction microorganism is an organism that is microscopic or submicroscopic, which is too small to be seen under naked eyes. Question 1 in the analysis check with your teacher before you. For the solutions to be usable in the lab for a titration, for instance, they must.
Solute is the dissolved substance and a solvent is the dissolving medium a dilution is the reduction of concentration of a solution by adding water. The teacher may wish to go step by step, making sure that all groups have. The organization, accuracy, completeness, interest in topic, results and explanations determine report grade. Sample lab 1 report 2 lab report 1 sample serial dilution of a bacterial culture introduction genetic analysis often requires the measurement of the frequency of events that are not likely to occur except in a large sample. Bacterial growth curve analysis and its environmental. Because of this, a variety of methods have been developed. Acids and bases usually come in concentrated form, as concentrates, but they are rarely used in this form. Ic50 assays, commonly used to evaluate drug efficacy, and assay development. The findings and conclusions in this report are those of the authors and do not necessarily represent the official. This represents 1 part patient sample added to 9 parts of diluent. Lab report overview each student is responsible for 50% of lab work, and for individual, original reports. Note that serial dilution is a special case of series of dilutions.
Here is an example of a lab report that was actually submitted and received a perfect grade along with stepby. Section 2 performing this lab, a serial dilution was set up for the red and blue dyes. A dilution is prepared by adding a specific amount of a concentrate to water. Serial dilutions involve diluting a stock or standard solution multiple times in a row. In other words, if the product is having too much bacterial count which is nearly uncountable, in that case also serial dilution is useful. Note, however, that such plating assays can only be used for bacteria that are, in fact, culturable. Following one weeks experiment could incubation at 25c, the colonies of the plate were change these and counted manually. For example, a tenfold serial dilution could result in the following concentrations.
Disscussion and conclusions the hypothesis for this lab was that serial from. Serial dilution techniques are routinely used in hospitals, public health, virology, immunology, microbiology, pharmaceutical industry, and food protection. So you can calculate the total effective dilution as. Dilutions in the range 101 110 to 108 1100,000,000 are generally used, although with particular types of samples the range of dilutions can be restricted. The initial concentration and target range needed determines the size and number of dilution steps required. Normal dilution dilution mls sample mls solvent total volume 1 to 10 1 0. Lab report 1 isolation, identification and use of serial. Disscussion and conclusions the hypothesis for this lab was that. Then, 1 ml from that mixture is added to 9 ml, and it is mixed together a 102 dilution. Calculate the number of moles and mass of cuso 4 5h 2 o s required to prepare 100.
Dilutions and concentrations introductory chemistry. The following formula can easily be used to carry out a simple dilution. Quantitative estimation of the number of viable microorganisms in bacteriological samples has been a mainstay of the microbiological laboratory for more than onehundred years, since koch first described the technique. Dilutions if a 18 dilution of the stock solution is made followed by a 16 dilution what is the final dilution. Dilution is the addition of solvent, which decreases the. For example, in 110 serial dilutions starting with a stock solution of 5m solute concentration, the serial dilution would be comprised of 5m, 0. This is a one millionfold dilution clearly too big to do at once. Lab reports can also be written for college classes, as well as other professional areas including engineering and computer sciences. It is critical that you master both serial and simple single dilutions. We will solve this problem by doing a serial dilution. Ic50 assays, frequently used to assess drug effectiveness, and assay growth procedures, as properly as standardcurve generation, involve the serial dilution of compounds, protein, or detection real. Lab report 1 isolation, identification and use of serial dilutions to estimate cell numbers. Conclusion we can determine the number of microorganisms in a sample by enumeration.
Serial dilutions may be used to prepare a series of standard concentrations for a biochemical assay, or to dilute a very dense culture of microorganisms to a concentration suitable. Your microbiology lab instructor taught you the basics of serial dilution and how to use it to determine the number of cells in an original bacterial culture. A series of five dilutions is made of this first dilution by diluting it 110, rediluting 110, and then three times more, each resulting solution then. We will report concentration in cfu per milliliter. This procedure is repeated until the desired concentration is reached. A solution is the mixture of 2 or more substances in the same phase. Use an appropriate dilution of the mixture with regard to the number of cells to be counted. Suitable garments include but are not limited to a lab coat, latex or nitrile.
Molarity, dilutions, and preparing solutions lab r. Making consistently accurate serial dilutions easier. Standard obligations in laboratory experiments such as preciseness in calculating and measuring numerous substances, as well as meticulousness are undoubtedly vital. Interested in isolation of soil bacteria lab report.
Typically, the dilution factor remains constant for each dilution, resulting in an exponential decrease in concentration. Serial dilutions austin community college district. After the incubation of plates, the number of cell can be counted. Many laboratory protocols require the serial dilution of reagents or. A serial dilution is a series of sequential dilutions used to reduce a dense culture of cells to a more usable concentration. A serial dilution is a dilution where a series of dilutions are conducted, each one may be onetenth as concentrated as the previous.
Objective plate count of water samples introduction the purpose of this experiment is to learn how to determine the number of microbes present in a given water sample through serial dilution, using the standard plate. Sample chem217 laboratory reports formal report format. Using a turntable and sterile bent glass rod see fig. The usage of burette was involved in the second experiment, disposing it up to 8. For example, one in perhaps a million trypanosomes may undergo a.
If the sample is not dissolved well, the cells become crowded and will be difficult to count. Ic50 assays, frequently used to assess drug effectiveness, and assay growth procedures, as properly as standardcurve generation, involve the serial dilution of compounds, protein, or detection real estate agents. Its commonly performed in experiments requiring highly diluted solutions, such as those involving concentration curves on a logarithmic scale or when you are determining the density of bacteria. Using this same procedure, 1 ml from the 10 2 dilution tube is transferred to the 103 dilution. Prelab questions show work and include in your lab report 1. Serial dilutionagar plate procedure to quantitate viable. Pdf lab report of microbiology akbar haqi academia. Even on this basic laboratory experiment requires of those standard obligations. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Estimation method for serial dilution experiments core.
Serial dilution is a series of dilutions used to determine the concentration or titer of a substance 6. In order to obtain a certain concentration of acid or base, dilutions are made. Dilution and concentration theory university of minnesota. Spectrophotometry page 7 of 10 single dilutions background stock solutions are constantly diluted in biological lab settings. The easiest method is to make a series of 1 in 10 dilutions.
Once organism is diluted out by certain dilution factor, it is allowed to inoculate on suitable nutrient media in petri dished. The objectives of this experiment are to learn the process of enumeration to determine the. However, the numbers of microorganisms in a given sample are required to know in certain aspect such as dairy industries, diseases investigation, and so on. I will be more than happy to help or answer any questions. Hypothesis predict how the serial dilution of your drink solution will affect the colour, flavor, and other properties of the solution. In this basic laboratory experiment, 100 ml 1 m solution of nacl and water was calculated and later mixed, before 1 ml of it was dropped into a 25 ml flask and was filled with water. A serial dilution is a series of stepwise dilutions, where the dilution factor is held. To detect the end point, multiple serial dilutions are inoculated into a suitable growth medium, and the development of some recognizable characteristic, such as acid production or turbidity, is used to indicate growth the presence of at least one viable microorganism in the diluted sample. Calculating serial dilutions serial dilutions are a way of dividing up a large dilution into a number of successive dilution steps with dilution factors of 100fold or less. Bio101 lab 3 bacteria enumeration north central college.