This website uses cookies to ensure you have the best experience. Learn more

Serial Dilutions Essay

1168 words - 5 pages

According to the Environmental Data Standards Council, a serial dilution is a numerical factor representing the number of equal volumes of diluent added to a sample (EDSC, 1). The process involving serial dilution is used to set up a series of different sample concentrations for an experiment. To accomplish this, a high concentration of sample is used as a starting point. A measured amount of sample is transferred to another well and mixed with dilution solvent, creating a lower concentration. For example, if 10 micro liters of sample is mixed with 90 micro liters of solvent, the resulting liquid will be 10% as concentrated. This is called a 1:10 dilution. Frequently in lab you may need ...view middle of the document...

The diluted material must then be thoroughly mixed to achieve the true dilution. For example, a 1:5 dilution (verbalize as "1 to 5" dilution) entails combining 1 unit volume of diluent (the material to be diluted) + 4 unit volumes of the solvent medium (hence, 1 + 4 = 5 = dilution factor). Example: Frozen orange juice concentrate is usually diluted in 4 additional cans of cold water (the dilution solvent) giving a dilution factor of 5, i.e., the orange concentrate represents one unit volume to which you have added 4 more cans (same unit volumes) of water. So the orange concentrate is now distributed through 5 unit volumes. This would be called a 1:5 dilution, and the OJ is now 1/5 as concentrated as it was originally. So, in a simple dilution, add one less unit volume of solvent than the desired dilution factor value (Abedon, 2-3).Serial Dilutions are a way for us to make solutions of varying concentrations very easily in succession. This method is desirable because it eliminates a lot of the uncertainty and vagueness involved in making very small concentrations relative to the stock solution. This method is based on the fact that there are two ways to achieve a 1 to 100 dilution. It can be done in one step adding 1 part solution to 99 parts water or by making a 1 to 10 dilution twice in a row, using the first made solution as the "stock" for the second dilution. Serial dilution is simply a series of simple dilutions which amplifies the dilution factor quickly beginning with a small initial quantity of material (i.e., bacterial culture, a chemical, orange juice, etc.). The source of dilution material for each step comes from the diluted material of the previous. In a serial dilution the total dilution factor at any point is the product of the individual dilution factors in each step up to it. An example of a three step 1:100 serial dilution of a bacterial culture (see figure below). The initial step combines 1 unit volume culture (10 ul) with 99 unit volumes of broth (990 ul) = 1:100 dilution. In the next step, one unit volume of the 1:100 dilution is combined with 99 unit volumes of broth now yielding a total dilution of 1:100x100 = 1:10,000 dilution. Repeated again (the third step) the total dilution would be 1:100x10,000 = 1:1,000,000 total dilution. The concentration of bacteria is now one million times less than in the original sample (4).Since serial dilutions are correlated...

Other Papers Like Serial Dilutions

Chemical Equilibrium Essay

4754 words - 20 pages determined to be 0.000229. The concentration of [FeSCN2+] was therefore determined by multiplying the absorbance value by the constant, k. Absorbance [FeSCN2+] 0.425 9.73 * 10-5 0.682 1.56 * 10-4 [FeSCN2+] = 1/4366.3*Absorbance (9) Experimental Procedure Spectrophotometer Practice Four serial dilutions were performed in order to gain practice in measuring the absorbance values of [FeSCN2+] at various diluted

Micro Term Review

3253 words - 14 pages bacterium represents a colony-forming unit (CFU). One or more plates should have a small enough number of colonies such that one is clearly distinguishable and can be counted. If you have made dilutions properly, you should get plates with a countable number of colonies (30 to 300 per plate). To count the actual number of colonies present, you would place the plate under the magnifying lens of a colony counter (Figure 6.8), and colonies on the

Freedom And Responsibility

2141 words - 9 pages Built within the Constitution of the United States are specifically defined freedoms that are guaranteed to all citizens. Conversely, with every constitutional freedom there comes a corresponding responsibility. On September 25, 1789, the state legislature’s twelve proposed amendments were transmitted by congress, the first two dealing with congressional representation and congressional pay. The following numbers three through twelve were

Hate Crime Laws

2348 words - 10 pages On June 7, 1998, 49-year-old James Byrd Jr. of Texas accepted a ride from three white men, who then beat him severely, urinated on him, chained him by his ankles to the back of their pick-up truck, dragged him for three miles into the countryside, and dumped his corpse in front of an African-American cemetery (Graczyk). A little over a year later, a jury sentenced ring leader John King to death by lethal injection (“Man Executed for Dragging

Rational Emotional Behavior Therapy Case Study Conceptualization And Treatment Plan

2140 words - 9 pages Rational Emotional Behavior Therapy Case Study of Sarah: A Conceptualization and Treatment Plan Rational emotive behavior therapy, REBT, was developed by Albert Ellis and holds the central belief that the events in our lives do not cause our disturbances but that they are instead caused by our view of the events (Murdock, 2009). Murdock (2009) states that “people are seen as responsible for their behavior” (p. 279) but, because they are

Holidays In Albania

1636 words - 7 pages Have you ever thought about having exciting and incredibly cheap vacations? Albania might be the right choice. According to My Travel Guide, Albania is ranked the fourth among ten places worth visiting in Eastern Europe (“Top 10 Eastern European Destinations”). One can encounter three kinds of vacations in this Mediterranean country: winter, summer, and cultural. The ideal places to spend your winter vacations are the Albanian Alps. They are

A Heart Of Darkness

1748 words - 7 pages In this short story, there are frequent significant subject and ideas that make the story, "A Heart of Darkness," by Joseph Conrad, and haunting novel. The main theme is absolute white power over the natives. The theme validates the corruption, and the dependence caused by the white people as they took over the Congo. White men were giving all the power; they had no self-control, and in the end they did not use wisely. The white men became

The Aspects Of Vulnerability Among The Exploited In Medical Research

2287 words - 10 pages Essentially, everyone is in some state of vulnerability. However, some of us are more susceptible to harm due to our vulnerabilities. The susceptible are the individuals with the greatest risk. These individuals risk the loss of their autonomy, and maybe even their lives. Vulnerable populations can be found in every subset of society. However, as previously mentioned, there are some vulnerable populations that are at an even greater risk than

The Hitchhiker’S Guide To The Galaxy

1171 words - 5 pages The Hitchhiker’s Guide to the Galaxy As the human race makes life-changing discoveries, it is made apparent that there is always more to learn as the universe, instead of becoming familiar, is becoming absurd. The Hitchhiker’s Guide to the Galaxy, written by Douglas Adams, as well as the 2005 film adaption, portrays absurdity to be an all-encompassing system in the universe. Through the introduction and attempt to understand lack of reason, the

The Ford Motor Company Wage Increase Of 1914 And The Theory Of Incentives And Efficiency Wages

1252 words - 6 pages ‘It’s not the employer who pays the wages. Employers only handle the money. It is the customer who pays the wages’ (Henry Ford, cited in Johnson and Weinstein 2004, p. 2). When the Ford Motor Company announced that it would more than double the wages of its workers in January 1914 to a ‘five-dollar day’ minimum, was this a contradiction to Henry Ford’s statement? If customers are actually the ultimate payers of wages, then more than

Historical Analysis Of The Economical Breakthroughs Of The Industrial Revolution

1396 words - 6 pages A Historical Analysis of the Economical Breakthroughs of the Industrial Revolution During the Industrial Revolution, many elements of society experienced huge breakthroughs that would change the way they functioned forever. Economics were definitely one of them. With many new inventions and many factories appearing, many, many, more resources were being created than ever before. Also, all of the revenue from these resources was being given to

Related Essays

How To Sleep Essay

1368 words - 6 pages media, incubationtemperature and time, and calculation method.(4) Serial Dilution Method (Most Probable Number Method)Use 12 test tubes: 9 containing 9 ml of soybean-casein digest medium each and 3containing 10 ml of the same medium each for control. Prepare dilutions using the 9tubes. First, add 1 ml of the test fluid to each of three test tubes and mix to make 10-times dilutions. Second, add 1 ml of each of the 10-times dilutions to each of

Lab Report

2443 words - 10 pages /10,000-1 - Different dilutions are prepared by dilution method. Dependent Density of yeast cells Cells per mm3 - - The number of yeast cells is estimated using a haemocytometer observed through a microscope. Controlled Standard yeast suspension - - Different yeast suspension used will affect the density of yeast cells All five dilutions are prepared using the same standard yeast suspension. Volume of yeast suspension used for each serial

Detection Of  Staphylococcus Aureus In Chicken Macaroni Salad

1674 words - 7 pages sample using a triple beam balance (Ohaus, 700/800 Series, USA). The food sample was then homognized with 225 mL of sterile Peptone Water (PW) (HiMedia, HiMedia Laboratories, India) using a sterile blender (Moullinex Type Q48, Mexico) for 60 sec at medium speed to make the 10-1 dilution. Ten-fold serial dilutions upto 10-3 were prepared by aseptically obtaining 1 mL from the homogenate and mixing with 9 mL of PW.         The dilutions were then

Sulphydryl Analysis

2488 words - 10 pages 31.5 microgms/ml of RNase of Molecular weight is 12,640. The mole of disulphide groups per ml of this solution was calculated. A standard curve of RNase solution using dilutions ranging from 1 to 10 nmoles disulphide per ml was prepared. And then all tubes were made to 1 ml. A solution without any disulphide was used as a blank. Including this blank there was needed 11 tubes. Duplicate tubes of 1:32 dilution of the lysozyme solution (0.5 mg/ml