Assay Answers
What is meant by an assay of 100.3% given on the label of a bottle of Na2EDTA*2H2O?
Q. I know that assays are supposed to quanitfy the amount of analyte, but how is 100.3% possible?
Asked by oops! - Sun Mar 28 14:30:13 2010 - Chemistry - 1 Answers - Comments
A. You are correct. More than 100% isn't physically possible. It just means that the amount in that bottle (or that lot of bottles) was quantitated at 100.3% when measured against standards or a calibration curve. The assay (test method) will have a bit of (allowable) error associated with it, and any value over 100% just makes this error really obvious. The error is usually a mix of instrumental and human error. Many pharmaceutical assays allow label claim errors of up to + or - 2%.
Answered by dfourmet - Sun Apr 4 13:31:09 2010
Q. I know that assays are supposed to quanitfy the amount of analyte, but how is 100.3% possible?
Asked by oops! - Sun Mar 28 14:30:13 2010 - Chemistry - 1 Answers - Comments
A. You are correct. More than 100% isn't physically possible. It just means that the amount in that bottle (or that lot of bottles) was quantitated at 100.3% when measured against standards or a calibration curve. The assay (test method) will have a bit of (allowable) error associated with it, and any value over 100% just makes this error really obvious. The error is usually a mix of instrumental and human error. Many pharmaceutical assays allow label claim errors of up to + or - 2%.
Answered by dfourmet - Sun Apr 4 13:31:09 2010
In an assay, why do all volumes need to be equal?
Q. When you're setting up an assay, why do all the volumes need to be equal before you read their absorbance? Why's it important? Thanks!
Asked by MarconisRadio - Sun Oct 3 12:44:09 2010 - Biology - 1 Answers - Comments
A. Dilution purposes. If you don't have the same volume, the absorbance will be read differently.
Answered by Shanks P - Sun Oct 3 12:45:27 2010
Q. When you're setting up an assay, why do all the volumes need to be equal before you read their absorbance? Why's it important? Thanks!
Asked by MarconisRadio - Sun Oct 3 12:44:09 2010 - Biology - 1 Answers - Comments
A. Dilution purposes. If you don't have the same volume, the absorbance will be read differently.
Answered by Shanks P - Sun Oct 3 12:45:27 2010
How do you determine protein concentration using the Bradford Assay?
Q. I am really confused, I am supposed to calculate protein concentration from several different tubes containing a protein solution. The units are in ug/u L. All I have is the amount of protein concentration for each tube expressed in u L, and the absorbance of each. How do I find the concentration? I have to make a graph of concentration vs. absorbance.
Asked by Liz - Mon Oct 20 13:43:52 2008 - Chemistry - 1 Answers - Comments
A. Use this formula to compute for the concentration: concentration = Absorbance (at wavelength used) divided by absorbance coefficient
Answered by sweeter_ion - Tue Oct 21 05:17:31 2008
Q. I am really confused, I am supposed to calculate protein concentration from several different tubes containing a protein solution. The units are in ug/u L. All I have is the amount of protein concentration for each tube expressed in u L, and the absorbance of each. How do I find the concentration? I have to make a graph of concentration vs. absorbance.
Asked by Liz - Mon Oct 20 13:43:52 2008 - Chemistry - 1 Answers - Comments
A. Use this formula to compute for the concentration: concentration = Absorbance (at wavelength used) divided by absorbance coefficient
Answered by sweeter_ion - Tue Oct 21 05:17:31 2008
What does it means by R square (R2) value for regression linear in standard curve of protein assay?
Q. I did Bradford assay to get a standard curve in order to determine the protein concentration. And i do get R square (R2)= 0.9789 which is closer to 1. But, i don't understand why it was said that the value closer to 1 is a better indicator to show that my standard curve is good to determine the protein concentration.
Asked by deane - Tue Jul 31 10:46:18 2007 - Mathematics - 2 Answers - Comments
A. The R^2 value (or the Pearson Coefficient of Determination) is an indicator of how well your data fits a line or curve. The closer the R^2 value is to 1 the better the data fits the curve. In other words, the closer the R^2 value is to 1 the more likely your data points are solutions to the equation that defines your curve. So if you have a line with the equation y=mx+b, the closer your R^2 value is to 1 the more likely that your data points x and y are actual solutions to the equation. This indicates how well your data fits the model you are testing. For a more technical description
Answered by spilzwon - Tue Jul 31 11:02:57 2007
Q. I did Bradford assay to get a standard curve in order to determine the protein concentration. And i do get R square (R2)= 0.9789 which is closer to 1. But, i don't understand why it was said that the value closer to 1 is a better indicator to show that my standard curve is good to determine the protein concentration.
Asked by deane - Tue Jul 31 10:46:18 2007 - Mathematics - 2 Answers - Comments
A. The R^2 value (or the Pearson Coefficient of Determination) is an indicator of how well your data fits a line or curve. The closer the R^2 value is to 1 the better the data fits the curve. In other words, the closer the R^2 value is to 1 the more likely your data points are solutions to the equation that defines your curve. So if you have a line with the equation y=mx+b, the closer your R^2 value is to 1 the more likely that your data points x and y are actual solutions to the equation. This indicates how well your data fits the model you are testing. For a more technical description
Answered by spilzwon - Tue Jul 31 11:02:57 2007
what way does a transient expression assay work?
Q. I cant find an actual step-by-step example online and was curious.
Asked by housti3 - Tue Apr 26 10:53:15 2011 - Biology - 1 Answers - Comments
A. Your question isn't very clear but I'll have a go. If you want to investigate an aspect of a protein (where it is, or when it's transcribed etc) you can make a fusion protein- for example you can fuse a fluorescent protein to your protein of interest so you can see it in a cell, or fuse the promoter of a protein to a reporter such as GUS or luciferase to show when the promoter is active. These proteins are normally looked at in multi-cellular organisms, but first you have to get your organism (for the sake of argument, a plant) to produce your fusion protein. There are 2 ways of doing this- creating "stable lines" or transient assays. Stable lines can potentially generate the protein throughout their lives (normally done by… [cont.]
Answered by LordYon13 - Tue Apr 26 11:29:35 2011
Q. I cant find an actual step-by-step example online and was curious.
Asked by housti3 - Tue Apr 26 10:53:15 2011 - Biology - 1 Answers - Comments
A. Your question isn't very clear but I'll have a go. If you want to investigate an aspect of a protein (where it is, or when it's transcribed etc) you can make a fusion protein- for example you can fuse a fluorescent protein to your protein of interest so you can see it in a cell, or fuse the promoter of a protein to a reporter such as GUS or luciferase to show when the promoter is active. These proteins are normally looked at in multi-cellular organisms, but first you have to get your organism (for the sake of argument, a plant) to produce your fusion protein. There are 2 ways of doing this- creating "stable lines" or transient assays. Stable lines can potentially generate the protein throughout their lives (normally done by… [cont.]
Answered by LordYon13 - Tue Apr 26 11:29:35 2011
You are going to do an enzyme assay, and you need to make a solution of substrate.?
Q. The concentration of substrate that you will use is 0.001 ug/ml. It is necessary to have enough for the enzyme assay. You will need to test 50 samples, plus a negative control lacking the enzyme, and another negative control lacking the substrate. You have determined that you will do all of this in triplicate. The assay calls for 1 ml of substrate solution and 0.2 ml of enzyme solution. If you don't have enough substrate solution, you will have to make more in the middle of the experiment, which could ruin your results. a. How much substrate solution should you make? b. How many grams of substrate will you need for this solution? c. How can you make this solution if you don't have a balance accurate enough to weigh such a small quantity? I… [cont.]
Asked by Lena - Fri Feb 23 07:16:10 2007 - Chemistry - 1 Answers - Comments
A. a. How much substrate solution should you make? 50 samples + a negative control (do all of this in triplicate) The assay calls for 1 ml of substrate solution Therefore, (50 + 1)x1 ml x 3 = 153 ml b. How many grams of substrate will you need for this solution? concentration of substrate that you will use is 0.001 ug/ml Therefore, 153 ml x 0.001 ug/ml = 0.153 ug c. How can you make this solution if you don't have a balance accurate enough to weigh such a small quantity? Weigh 1.0mg of substrate and dissolve it in 1000 ml buffer solution in a volumetric flask (stock solution). The resulting concentration will be 1.0 mg/1000ml = 0.001mg/m L (i.e. 1 ug/ml ) Take 1ml from stock solution and dilute it to 1000 ml with buffer solution in a… [cont.]
Answered by Yy - Fri Feb 23 10:03:34 2007
Q. The concentration of substrate that you will use is 0.001 ug/ml. It is necessary to have enough for the enzyme assay. You will need to test 50 samples, plus a negative control lacking the enzyme, and another negative control lacking the substrate. You have determined that you will do all of this in triplicate. The assay calls for 1 ml of substrate solution and 0.2 ml of enzyme solution. If you don't have enough substrate solution, you will have to make more in the middle of the experiment, which could ruin your results. a. How much substrate solution should you make? b. How many grams of substrate will you need for this solution? c. How can you make this solution if you don't have a balance accurate enough to weigh such a small quantity? I… [cont.]
Asked by Lena - Fri Feb 23 07:16:10 2007 - Chemistry - 1 Answers - Comments
A. a. How much substrate solution should you make? 50 samples + a negative control (do all of this in triplicate) The assay calls for 1 ml of substrate solution Therefore, (50 + 1)x1 ml x 3 = 153 ml b. How many grams of substrate will you need for this solution? concentration of substrate that you will use is 0.001 ug/ml Therefore, 153 ml x 0.001 ug/ml = 0.153 ug c. How can you make this solution if you don't have a balance accurate enough to weigh such a small quantity? Weigh 1.0mg of substrate and dissolve it in 1000 ml buffer solution in a volumetric flask (stock solution). The resulting concentration will be 1.0 mg/1000ml = 0.001mg/m L (i.e. 1 ug/ml ) Take 1ml from stock solution and dilute it to 1000 ml with buffer solution in a… [cont.]
Answered by Yy - Fri Feb 23 10:03:34 2007
what is the principle of the DPPH free radical inhibition assay?
Q. and what has the DPPH assay got to do with absorbance and percent inhibition? i dont know how to interpret my results. and oh yeah i need sources :)
Asked by marketer - Sun Mar 1 12:10:59 2009 - Medicine - 1 Answers - Comments
A. Read that website
Answered by adel a - Wed Mar 4 20:14:04 2009
Q. and what has the DPPH assay got to do with absorbance and percent inhibition? i dont know how to interpret my results. and oh yeah i need sources :)
Asked by marketer - Sun Mar 1 12:10:59 2009 - Medicine - 1 Answers - Comments
A. Read that website
Answered by adel a - Wed Mar 4 20:14:04 2009
What is a membrane fragility assay? What's the significance of the result for this assay? ?
Q. What is a membrane fragility assay? What's the significance of the result for this assay? thanks
Asked by student - Tue Sep 9 10:42:49 2008 - Biology - 1 Answers - Comments
A. The Cell membrane generally constitutes an initial line of protection for the cell and hence for the entire organism for that matter. This basic tennet underlines the various interests and hitech methods for evaluating the intrinsic membrane characteristics: its stability, fluidity, deformability and other viscoelastic properties . Extended to the human red blood cells (RBC) specific alteration of any of these factors are frequently implicated in many physiological and pathophysiological processes, including various erythrocyte based hereditary disorders Estimation of the osmotic fragility (OF) of RBCs for example exploits the specific structural changes which the RBC membrane undergoes when the cell is subjected to osmotic stress Properly… [cont.]
Answered by Peter S - Sat Sep 13 06:46:39 2008
Q. What is a membrane fragility assay? What's the significance of the result for this assay? thanks
Asked by student - Tue Sep 9 10:42:49 2008 - Biology - 1 Answers - Comments
A. The Cell membrane generally constitutes an initial line of protection for the cell and hence for the entire organism for that matter. This basic tennet underlines the various interests and hitech methods for evaluating the intrinsic membrane characteristics: its stability, fluidity, deformability and other viscoelastic properties . Extended to the human red blood cells (RBC) specific alteration of any of these factors are frequently implicated in many physiological and pathophysiological processes, including various erythrocyte based hereditary disorders Estimation of the osmotic fragility (OF) of RBCs for example exploits the specific structural changes which the RBC membrane undergoes when the cell is subjected to osmotic stress Properly… [cont.]
Answered by Peter S - Sat Sep 13 06:46:39 2008
Should you always assume a linear relationship between conc. of DNA and fluorescence in the picogreen assay?
Q. My data for the detection of a DNA plasmid always fits a perfect curve, a linear fit can be assigned to the lower portion of the data. I dont know how to best deal with the data, should I just use the points that may fit linearity or treat the data as a curve? Thanks wise duck, however my data does not plateau as in the case of saturation, I have seen this often in immunoassay, rather it rises exponentially.
Asked by babybaleno - Thu Jan 31 07:52:04 2008 - Biology - 1 Answers - Comments
A. The concentration vs absorbance is only accurate during the linear part of the curve. As you approach saturation the number is unreliable.
Answered by Weise Ente - Thu Jan 31 09:05:29 2008
Q. My data for the detection of a DNA plasmid always fits a perfect curve, a linear fit can be assigned to the lower portion of the data. I dont know how to best deal with the data, should I just use the points that may fit linearity or treat the data as a curve? Thanks wise duck, however my data does not plateau as in the case of saturation, I have seen this often in immunoassay, rather it rises exponentially.
Asked by babybaleno - Thu Jan 31 07:52:04 2008 - Biology - 1 Answers - Comments
A. The concentration vs absorbance is only accurate during the linear part of the curve. As you approach saturation the number is unreliable.
Answered by Weise Ente - Thu Jan 31 09:05:29 2008
How many average plaques do you get when doing an immunological plaque assay with s RBC's as antigen?
Q. We have to write up a report on plaque assay, however we did not get any results in any of our petri dishes!! Is there an average of how many plaques are produced??
Asked by Choca - Fri Jan 22 08:43:31 2010 - Biology - 1 Answers - Comments
A. 5
Answered by lazytramp789 - Mon Jan 25 11:06:27 2010
Q. We have to write up a report on plaque assay, however we did not get any results in any of our petri dishes!! Is there an average of how many plaques are produced??
Asked by Choca - Fri Jan 22 08:43:31 2010 - Biology - 1 Answers - Comments
A. 5
Answered by lazytramp789 - Mon Jan 25 11:06:27 2010
What is the difference between a standard and a blank in protein assay?
Q.
Asked by Kari - Mon Oct 11 16:48:29 2010 - Biology - 1 Answers - Comments
A. A blank has zero protein in it. A standard has a known amount of protein in it.
Answered by Smeghead - Tue Oct 12 16:30:26 2010
Q.
Asked by Kari - Mon Oct 11 16:48:29 2010 - Biology - 1 Answers - Comments
A. A blank has zero protein in it. A standard has a known amount of protein in it.
Answered by Smeghead - Tue Oct 12 16:30:26 2010
Why do a quantitative PBG assay if the Watson-Schwarz test is negative?
Q. Hi, I have one question in regards to porphyrin screening test and Watson-Schwarz test. If you could answer this one, I will appreciate it.
Asked by sean - Sun Oct 18 05:13:02 2009 - Medicine - 1 Answers - Comments
A.
Answered by sameer s - Mon Oct 19 07:21:58 2009
Q. Hi, I have one question in regards to porphyrin screening test and Watson-Schwarz test. If you could answer this one, I will appreciate it.
Asked by sean - Sun Oct 18 05:13:02 2009 - Medicine - 1 Answers - Comments
A.
Answered by sameer s - Mon Oct 19 07:21:58 2009
How do you know which type of viral assay method to use for a particular virus? (Hemagluttination assay etc.)?
Q. What are the purposes of different assays?
Asked by Matt - Fri Oct 23 16:19:51 2009 - Biology - 1 Answers - Comments
A. Different viruses have different characteristics that require different methods. Also, what you are testing will determine what kind of assay you need. If there was only one assay, only one virus could be tested for one thing.
Answered by J - Fri Oct 23 16:38:38 2009
Q. What are the purposes of different assays?
Asked by Matt - Fri Oct 23 16:19:51 2009 - Biology - 1 Answers - Comments
A. Different viruses have different characteristics that require different methods. Also, what you are testing will determine what kind of assay you need. If there was only one assay, only one virus could be tested for one thing.
Answered by J - Fri Oct 23 16:38:38 2009
What is the Assay Process in Determining a Worthy Gold Site?
Q. Suppose you believe you have discovered gold in a river or possibly underground. Well, how does one get this confirmed or denied?
Asked by houstonpackard - Thu Jun 14 13:54:10 2007 - Chemistry - 2 Answers - Comments
A. The classic gold assay in ore is the cupel, Google cupel gold 18,30 hits If it is gold in a water environment and it is honest (re Bre-X), it should have a much lowered silver content from corrosion. Quick checks are density, streak plate, resistance to concentrated nitric acid; melt (1064 C) not burn in a torch flame on charcoal. Dissolve in aqua regia and precipitate the Purple of Cassius on tin hydroxide sol.
Answered by Uncle Al - Thu Jun 14 14:41:52 2007
Q. Suppose you believe you have discovered gold in a river or possibly underground. Well, how does one get this confirmed or denied?
Asked by houstonpackard - Thu Jun 14 13:54:10 2007 - Chemistry - 2 Answers - Comments
A. The classic gold assay in ore is the cupel, Google cupel gold 18,30 hits If it is gold in a water environment and it is honest (re Bre-X), it should have a much lowered silver content from corrosion. Quick checks are density, streak plate, resistance to concentrated nitric acid; melt (1064 C) not burn in a torch flame on charcoal. Dissolve in aqua regia and precipitate the Purple of Cassius on tin hydroxide sol.
Answered by Uncle Al - Thu Jun 14 14:41:52 2007
how can you assay pepsin activity using basic materials?
Q. I know that there is a procedure using hemoglobin and many other complicated solutions that i dont have access to, is there a way to assay the activity of the pepsin enzyme using school science materials?
Asked by Ibrahim Nakhal - Sun Nov 14 05:34:00 2010 - Biology - 1 Answers - Comments
A. don't think so
Answered by Jiawei - Sun Nov 14 06:33:19 2010
Q. I know that there is a procedure using hemoglobin and many other complicated solutions that i dont have access to, is there a way to assay the activity of the pepsin enzyme using school science materials?
Asked by Ibrahim Nakhal - Sun Nov 14 05:34:00 2010 - Biology - 1 Answers - Comments
A. don't think so
Answered by Jiawei - Sun Nov 14 06:33:19 2010
Doing a HTP assay, why do you measure fluorescence and absorbance?
Q. I'm doing an experiment on endocytosis - and measuring the level of uptake for cells by putting dye in the extracellular environment. We are testing this on two different cell lines. We are told to measure fluorescence and absorbance, and I think fluorescence/absorbance is used as our measurement for how much endocytosis went on. Can anyone explain to me why we use absorbance, and why we divide. Is it to standardise, and if so, how?
Asked by Daniel Plainview - Sat May 14 08:15:06 2011 - Biology - 1 Answers - Comments
A. absorbance is probably use to get an idea about how many cells there are in your experiment - it will allow you to report your data as "uptake per cell" (or something similar) - this makes it possible for others to compare your data to theirs (since they may not necessarily use the same cell density as you do)
Answered by Horst S - Sat May 14 09:25:08 2011
Q. I'm doing an experiment on endocytosis - and measuring the level of uptake for cells by putting dye in the extracellular environment. We are testing this on two different cell lines. We are told to measure fluorescence and absorbance, and I think fluorescence/absorbance is used as our measurement for how much endocytosis went on. Can anyone explain to me why we use absorbance, and why we divide. Is it to standardise, and if so, how?
Asked by Daniel Plainview - Sat May 14 08:15:06 2011 - Biology - 1 Answers - Comments
A. absorbance is probably use to get an idea about how many cells there are in your experiment - it will allow you to report your data as "uptake per cell" (or something similar) - this makes it possible for others to compare your data to theirs (since they may not necessarily use the same cell density as you do)
Answered by Horst S - Sat May 14 09:25:08 2011
what assay to use to determine a serotype?
Q. which serotype of chlamydia one has for example. what assay can be done to determine it?
Asked by Teez - Fri Apr 3 04:56:51 2009 - Biology - 1 Answers - Comments
A. Plaque assay can be used for infectivity of the different serotypes of chlamydia type I and II. There are many types of tests to detect the different strains, but i think the common ones are: 1. Mouse toxicity prevention test 2. Microinmmunofluorescence test Hope that helps, good luck
Answered by playpwnsu - Fri Apr 3 07:40:18 2009
Q. which serotype of chlamydia one has for example. what assay can be done to determine it?
Asked by Teez - Fri Apr 3 04:56:51 2009 - Biology - 1 Answers - Comments
A. Plaque assay can be used for infectivity of the different serotypes of chlamydia type I and II. There are many types of tests to detect the different strains, but i think the common ones are: 1. Mouse toxicity prevention test 2. Microinmmunofluorescence test Hope that helps, good luck
Answered by playpwnsu - Fri Apr 3 07:40:18 2009
I want to know the method of assay of tramadol and rupatadine from tablets?
Q. I am a student of Pharmaceutics working on various formulations of tramadol and rupatadine.
Asked by hithunderbolt - Tue Aug 21 05:43:46 2007 - Medicine - 1 Answers - Comments
A. I mostly get information from Wikipedia. Even though it is not a "reliable" source, there is some complex information.
Answered by dmknappy - Tue Aug 21 19:44:24 2007
Q. I am a student of Pharmaceutics working on various formulations of tramadol and rupatadine.
Asked by hithunderbolt - Tue Aug 21 05:43:46 2007 - Medicine - 1 Answers - Comments
A. I mostly get information from Wikipedia. Even though it is not a "reliable" source, there is some complex information.
Answered by dmknappy - Tue Aug 21 19:44:24 2007
What is a kinase assay and how is it performed?
Q. I have never carried out a kinase assay or been taught about its theory could anyone please explain this to me? I am at university and it has never been included in my course but I came across it in a paper and thought I should find out about it. If anyone can even point me in the direction of a good website that would be great. Thanks.
Asked by Kara P - Fri Mar 13 20:25:12 2009 - Biology - 1 Answers - Comments
A. Kinases are a very important class of enzymes found in the cell. They transfer the outermost phosphate (the gamma-phosphate) from a molecule of ATP onto a serine, threonine, or tyrosine amino acid in a target protein (i.e., kinases "phosphorylate" their substrate proteins). In order to measure this enzymatic activity, scientists often use an in vitro kinase assay. There are a bunch of variations of this technique, but perhaps the most common is as follows: Cells that express the kinase you want to study are lysed with detergent to produce crude cell lysate in a tube. An antibody specific to the kinase you want to study is added to the cell lysate. The antibody will bind to your target kinase. The mixture is incubated with large… [cont.]
Answered by Anand S - Fri Mar 13 21:00:48 2009
Q. I have never carried out a kinase assay or been taught about its theory could anyone please explain this to me? I am at university and it has never been included in my course but I came across it in a paper and thought I should find out about it. If anyone can even point me in the direction of a good website that would be great. Thanks.
Asked by Kara P - Fri Mar 13 20:25:12 2009 - Biology - 1 Answers - Comments
A. Kinases are a very important class of enzymes found in the cell. They transfer the outermost phosphate (the gamma-phosphate) from a molecule of ATP onto a serine, threonine, or tyrosine amino acid in a target protein (i.e., kinases "phosphorylate" their substrate proteins). In order to measure this enzymatic activity, scientists often use an in vitro kinase assay. There are a bunch of variations of this technique, but perhaps the most common is as follows: Cells that express the kinase you want to study are lysed with detergent to produce crude cell lysate in a tube. An antibody specific to the kinase you want to study is added to the cell lysate. The antibody will bind to your target kinase. The mixture is incubated with large… [cont.]
Answered by Anand S - Fri Mar 13 21:00:48 2009
where can i find a method to assay an antibiotic?
Q. can anyone tell me a method to assay an antibiotic and/or an antiseptic? or send me a link? thanks
Asked by Elle - Mon Feb 8 13:47:36 2010 - Chemistry - 1 Answers - Comments
A. Which one? What concentration range in what kind of sample? The procedure will be different if you're testing that a tablet is 99.% pure antibiotic, versus measuring 100 ppb levels of antiseptic in waste water. The generic approach is some kind of chromatography - either HPLC or GC, depending on the sample, concentration, the kind of detector you want to use, and whether the antibiotic is stable at high temperature (many aren't). You'd need a small amount of the pure material to prepare standards (so that you know which peak in the chromatogram corresponds to the antibiotic you're looking for, and so that you know how much peak area corresponds to how much mass or concentration of antibiotic). Depending on which antibiotic you're looking… [cont.]
Answered by Mike S - Mon Feb 8 16:01:30 2010
Q. can anyone tell me a method to assay an antibiotic and/or an antiseptic? or send me a link? thanks
Asked by Elle - Mon Feb 8 13:47:36 2010 - Chemistry - 1 Answers - Comments
A. Which one? What concentration range in what kind of sample? The procedure will be different if you're testing that a tablet is 99.% pure antibiotic, versus measuring 100 ppb levels of antiseptic in waste water. The generic approach is some kind of chromatography - either HPLC or GC, depending on the sample, concentration, the kind of detector you want to use, and whether the antibiotic is stable at high temperature (many aren't). You'd need a small amount of the pure material to prepare standards (so that you know which peak in the chromatogram corresponds to the antibiotic you're looking for, and so that you know how much peak area corresponds to how much mass or concentration of antibiotic). Depending on which antibiotic you're looking… [cont.]
Answered by Mike S - Mon Feb 8 16:01:30 2010
From Yahoo Answer Search: 'assay'
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