New Order Received

I just received a new shipment of materials on Friday- it has taken me all weekend to catalog it all, but I finally have it all put away. Here it is cataloged the price of each of the things that I got- I included dH₂O so that one would have a basis for the pricing (that is priced as it is priced at Fred Meyer).

Cupric Chloride:                 $25.50/ mol           

Bleach                                   $0.76/ mol           

Deionized water:                   $0.04/ mol           

Crystal Violet:                   $676.47/ mol           

Methylene Blue:                  $29.82/ mol           

Sucrose:                               $38.71/ mol           

Fructose- Low glucose:       $18.20/ mol           

Maltose- Monohydrate:      $287.46/ mol           

Benedict’s Reagent:            $10.59/ mol           

Biuret Reagent:                        $301.11/ mol           

Electrophoresis gel:         $1,622.41/mol           

Now, you are probably wondering what most of these things do, or are used for in a lab. To start, CuCl₂ is a chemical that can be commonly found in labs, although it is most commonly used to show the humidity in a room (it is an indicator test, as it turns blue the more water that is present). Bleach is a surefire way to clean- even after using alcohol, one should still use bleach, to make sure that all proteins have been broken down. Deionized water is a negative control, as it is neutral and does not have anything that one in a biological lab would be looking for, for the most part. Crystal violet is a dye, the first step of a gram stain, which is what is commonly used on microscope slides. It is a purplish blue dye that indicates the presence of peptidoglycan, which is found in the cell ways of bacteria. It is the positive side of the test, with the negative side (not mentioned here by pricing- I did not order any of it, as I accidentally ordered two the last time) being safranin, which is a pinkish stain. Methylene blue is used for two things that the reader should be interested in- one is a use in chemistry, the other in biology. In chemistry, this is used as an indicator with Redox (Oxidation Reduction) reactions, and relies on pH, and turning either clear or blue depending on the way one goes with the reaction or adding more of one substance. In biology, it is used as a stain in gel electrophoresis gels with DNA and RNA, as it clings to nucleic acids among other things (it also turns the gel blue). It is also used to see if yeast are alive or not- living cells work to keep methylene blue out of them, and, as a result remain unstained, while dead ones obviously do not care about what goes into or out of them, and it stains them blue.

Sucrose, fructose, glucose and maltose are all sugars- maltose comes from starch that is broken down by amylase, and is made up of glucose, so many of those indicators are the same. Benedict’s reagent is used to test for sugar- ironically, the list of sugars it indicates include maltose and glucose. It is usually blue in color, and is added to the solution one wishes to test, then heated after being mixed quite well. As it is heated, if there is maltose or glucose present, it turns slowly to a muddy, tomato soup color, after going through many different stages of color. The speed is something to watch, as that is an indicator of the amount, and if the samples are all allowed to heat for the same amount of time at the same heat (although the heat does not make it move faster or slower), they can be compared to each other and to a known quantity (or quantities) to find out about how much of those sugars are present. Biuret’s reagent tests for proteins- it also is blue when alone, but it turns pink or purple depending on what is present in the sample. No heating is required or even wanted with Biuret’s reagent. Earlier, I touched on gel electrophoresis. Gel electrophoresis is the separating of particles based on size, shape, density, charge, and mass. The gel is like that in some petri dishes- agar or agarose, depending on who you talk to- but is not designed to grow bacteria. I merely purchased the powder, as one should not purchase the gels but mix them themselves, as then one knows of any possible contamination. Instead, it is made to be rectangular to fit a mould, and then has a comb-like object inserted into it, then taken out to make wells in which to put the fluids. It is then put into a special box that runs electrical current through it, and depending on the aforementioned attributes, the particles in the fluids move through the gel to get to the side that attracts them. All DNA molecules are negatively charged so they go to the right, where the positive side of the box is, as opposites attract. After letting the gels run at a slightly high voltage (too low, and the particles don’t move, too high and the gel melts or the particles leave the gel, or both) for a while, one turns off the box, and stains the gel with methylene blue or a similar dye (most of the others are toxic, while people actually sometimes take methylene blue because, according to Dr. Wikipedia, it is good for your health [I’m sure other doctors have said that, but I could only find it on Wikipedia when I searched]), and looks at the gel on top of a light, where they put a sheet of acetate over the top and trace the shapes in the gel. This process is quite fun and informative, provided one does not poke through the gel, which creates a mess, as one has a whole bunch of buffer in there with the gel to keep it safe from cooking while the gels are running.

Below are the chemical formulas of each of these items, as well as the weight (in grams) of the compound so that those of you unused to reading in moles know about how large it is:

Cupric Chloride:              CuCl₂ x 2H₂O                                                  170.49 g

Bleach:                              NaClO                                                                74.44 g

Deionized water:              dH₂O                                                                  18.02g

Crystal Violet:                  [(CH₃)₂NC₆H₄]₂C: C₆H₄:N(CH₃)₂Cl            245.82g

                                                              C₁₃H₂₆N₂Cl

Methylene Blue:               C₁₆H₁₈ClN₃S x 3H₂O                                    337.87 g

Sucrose:                            C₁₂H₂₂O₁₁                                                      342.30 g

Fructose- Low glucose:    C₆H₁₂O₆                                                          180.16 g

Maltose- Monohydrate:    C₁₂H₂₂O₁₁ x H₂O                                           360.32 g

Benedict’s Reagent:          Na₂CO₃+Na₃C₆H₅O₇+CuSO₄                      511.66 g

                                                           Na₅CuC₆O₁₄H₅S

Biuret Reagent:                 C₂H₅N₃O₂)₇                                                                    103.09 g

Electrophoresis gel:           C₂₄H₃₈O₁₉                                                      630.55g

Now that you know something more about these, one should also note where they have been put in the lab, as some of these things are very flammable and all reputable sources for them require you to show proof of identity to buy them, as only teachers or commercial labs can buy them. The dyes are all in the back room, grouped together in the very back part of the room- they are all very flammable. The sugars are all stored on a shelf near them, as is the agarose. OSHA does not believe the sugars to be hazmat, but they are pretty expensive, and one would want to keep them all safe from spillage. The only thing on that shelf with any sort of danger of fire is the agarose, which has a fire rating of 1- slightly hazardous. It probably will not be spontaneously combusting anytime soon. The bleach will not catch fire- therefore, it is safest to use around the dyes, as the alcohol can catch fire more easily. The water is obviously safe, and the Cupric (or Copper (II)) Chloride is not very flammable either. One must always treat everything in a lab like it possibly contaminated- therefore, one must always wear gloves and hair back, as well as exercising caution whenever walking around. In addition, one should always wear a lab coat (they are now made to be flame retardant, although after being washed in bleach, that sort of goes away. So they are dry-clean only) or an apron when dealing with hazardous chemicals, and when mixing things, wear goggles in case of contamination of the substance, which could cause an explosion. Never breathe in the fumes or smell anything in a lab, and do not drink anything either, unless it says on the container that it is safe to drink. Even though you wear gloves, wash your hands often. This is, obviously, basic stuff, but sometimes people need a reminder. The dyes tend to stain clothing, which is quite often unwanted, so that is a second reason to wear a lab coat. The next best reason after that is- because it is cool, and who would not want to wear a lab coat?

Finally, where to look. One should search these all on either the Carolina website (http://www.carolina.com), the Avantor website (http://www.avantormaterials.com) or ScienceLab (http://www.sciencelab.com) to find these materials. Search by the exact name to find them- unfortunately, they are sold by weight, not moles, but I have been able to convert them to be price per mole. Remember, have fun and stay safe! If it says flammable, don't go near it with a lit match!