why lab rules are important?
87988
because they help you to do your thing without contaminig destroying what ur working on and equipment and not to endanger urself and others in a lab
1042407
Its best to consult your lab manula or technician.
440553
Because you mention Rf values, I assume you're asking specifically about Thin-Layer Chromatography.  Actually the molecular weight is a fairly minor factor in the Rf value.  Intermolecular interactions between the pigment in question and the solid phase and the mobile phase are the most important.  So it really comes down to the selection of the mobile phase, how polar, how acidic or basic in relation to the analyte (your pigment in this case).  pH of the mobile phase is critically important in that your pigment may ionize to a greater or lesser extent depending upon the pH, and this drastically changes the intermolecular interactions.  Stationary phase selection is also important.
1134495
Check your Chemistry Laboratory Guide.
739678
take a wild guess....so there are no disasters and so you at least have some education in the lab before you enter it
374011
It doesn't if the substance that is being tested is a liquid.  If the substance is a solid, then you need water to facilitate the interaction between the substance and the litmus.
794268
To learn how to make media. To learn to culture and split cells. To know contamination when you see it. Microscopy. Cell counting; by Coulter and hemocytometer. And a whole lot more, but these will do for a start.
153314
If it counts as a chemistry discovery, the periodic table is definitely the most important.  It allows chemists to predict the chemical properties of known and undiscovered elements, including boiling and melting points, reactivity, and potential bonding.  It also provides the basis for determining the formulae of molecules and compounds, which is absolutely fundemental for chemistry.  Any chemist will tell you that the periodic table is an essential tool for chemistry.
607610
I have no idea on the exact reason (was it a committee decision?). However, 20 deg C is room temperature. This is an easy temperature to achieve and it probably really close to the temperature of the lab where they would be taking this measurement. In short, convenience
364687
Every medical laboratory is to some extent unique. This lab uses that reagent supplier for blood tests, and some other supplier for tissue tests, and so on. Another lab uses a different collection of suppliers. And, different labs use different procedures to some extent (eg, different workloads of facility layouts). And there are often several different equipment vendors, whose equipment works slightly differently, using different operational sequences and check points.\n\nSo, the very same sample (at least taken from a single larger original sample anyway) will give slightly different results in every lab for most any particular test. In order to lessen the chance of confusion, labs report a 'norm' value for many tests to tell those interpreting the test that our values run <a little higher than the literature reports...> or something similar. They also usually supply a 'normal range' for each test as a courtesy to whoever has to look at the reports; people vary quite a lot, and this value might be acceptable in you but not in someone else quite apart from any laboratory norm differences from other labs.\n\nSince the values in clinical lab reports are often used to decide questions of diagnosis and treatment, it's pretty important (actually vital) to be certain the lab's results are as claimed. And certainly that any errors which can be caught are actually identified. There is a small industry of calibrated sample suppliers and operational testing to ensure this. \n\n==========\nblood glucose testing example\n\nTake, for instance, the home blood glucose monitors used by many diabetics. These generally come with a small bottle of test solution (or control solution, depending on who is choosing names). This is carefully concocted 'fake blood' with a pre-determined concentration of glucose. By using it (if it hasn't partially evaporated or deteriorated), one can test the operation of the glucose meter/test strip combination, qualitatively -- and to some extent quantitatively. A similar dodge is used in actual laboratories. To avoid 'fudging' in the labs themselves (a kind of Caesar's wife's reputation sort of thing), test reagents are generally not made locally, but rather in a central facility.\n\n======\nregulation, licensing, accreditation\n\nLabs are also supervised by industry accrediting bodies rather like colleges, and almost always have statutory and regulatory supervision (mandatory licensing, for example). \n\n======\nmalfeasance\n\nDespite all of this, it's still possible for mendacious lab operators to perform poorly. Especially in circumstances which require some subjective evaluation. A recent example in the US, though not exactly a laboratory issue, is the exposure of what seems to have been a litigation fraud involving lung diseases caused by mining or industrial operations. Attorneys have advertised for plaintiffs, provided testing for them, and organized suits for damages based on the results. The tests (X-rays and the interpretation thereof, primarily) were performed by  independent contracting physicians and X-ray labs, but it seems that several folks noticed that business depended on the findings. There were an awfully large number of folks found to have lung disease who may not have had it all, or at least not the disease for which damages were being sought. Just who arranged for it all, beyond a small number of doctors who made quick diagnoses from medical files, usually without actually meeting patients, is not clear. The lawyers certainly benefited in that they found clients for whom ot work. The patients benefited, though often not very much as individual settlements were often not large. As the situation is clarified, we may learn more as to who organized it, if there is indeed a single organizing brain. \n\nPsychological testing is not very lab based, but the same (or something similar) kind of problem has been noticed in exert evaluations
852174
Sounds like a typo.  Call the lab that performed the test.
334748
Typically labs have densitometers for gel electrophoresis analysis.  There has also been increasing use of capillary electrophoresis systems for IFE/s and SPE.
552969
Microbiology is essential to the practice of medicine in many ways. The diagnosis and treatment of disease caused by microbes - i.e., infections - relies on the microbiology lab. Lab samples (urine, blood, wound swabs etc.) are sent for "culture and sensitivity" to find out what bacteria are present, and which antibiotics will kill them. \n\nHospital microbiologists are experts in knowing which bacteria are around, the best choice of antibiotics (and the route - oral or intravenous) for any given patient, and they are also invaluable in terms of infection control planning (to stop the spread of infections in hospitals, try to limit the development of antibiotic resistance, etc.) We call our microbiologist at least once a week, usually for advice on antibiotic coverage.\n\nHowever, if you're referring to the production of medications, microbiology is highly relevant in that some new meds are produced by bacteria using recombinant DNA technology. Bacteria and yeast are very easy to manipulate, in terms of their DNA. It is fairly straightforward to take the DNA that codes for a protein such as human insulin, snip it out of the human genome, stick it into the bacterial DNA, and then you have a colony of bacteria that will happily make lots of human insulin for patient use. (This is a huge improvement over extracting it from cows, for instance.) The "clot-busting drug" tPA (tissue plasminogen activator), used to treat strokes and heart attacks, is also made this way.
621903
So that there are no pollutants that might possibly influence your results.  Same with dry - water might change the way that some chemicals react against each other.
529016
The "amount" of each compound present in the reaction.  While most will tell you that it technically is in terms of "moles", it can just as easily be thought of as a recipe.  \nIf you wanted to create a particular substance in the lab, these amounts would give you an idea of the amount of reactants needed to synthesize the end material.
118581
It typically includes a chemical analysis to detect Protein,  and Sugar. The urine is checked for pH (acidity) snd concentration (gravity). And finally there is a microscopic analysis to see if there are any abnormal cells present.
966917
Gram staining is a laboratory test used for identifying various kinds of bacteria.  Some kinds of bacteria react to the stain and those are gram positive, the rest don't and they are gram negative.  Different kinds of antibiotics are designed to kill bacteria that are gram positive, gram negative or both.