Nanodrop

     Some experimenters may find a need to know the concentration of a certain substance, usually a plasmid (circular DNA). In order to find out how much DNA you have, you could use a spectrophotometer. However, normal spectrophotometers usually use about 1mL of a sample. In most cases, you do not have this much plasmid. In order to measure the concentration using a small amount of plasmid, you can use a nano spectrophotometer, referred to as Nanodrop.
     If you have access to a nanodrop, install the software on your computer, and click on ND1000 to open the software. Select the nucleic acid setting if you are measuring DNA . Make sure DNA-50 is selected in the top right. Wipe both the upper and lower terminals with nanopure to clean the terminals. Then, initialize the instrument with water by placing 2uL of nanopure water on the sample pedestal, lowering the arm, and clicking okay. Then clean the pedestal to remove the water. Next, blank the insturment by placing 2uL of your elution buffer (ex. TE, Tris HCL, etc.) on the pedestal and clicking blank. It is important to blank the instrument using the buffer your DNA is in to account for any background absorbance from the buffer. Then, clean off the pedestal again. Finally, measure your sample by placing 2uL of it on the pedestal and clicking measure. The output is in ng/uL. Record the 260/280 value and the 260/230 value. These ratios will give you the purity of the DNA if you need it. Print out your graph.

     To be more accurate, take a second measurement and average the readings. The concentration of plasmids are usually abbreviated using the symbol λ, which means ug/uL. If your value is 1.5λ, then that is equal to 1.5ug/uL, which is equal to 1500ng/uL.

The Use of Micropipettes

     Scientists use micropipettes when dealing with very small amounts of liquid. The samples micropipettes can take range from 0.01 uL (microliters, or 10^-6 of a liter) to about 1000uL (1mL). The following table shows different pipette sizes and their tips:

     In addition to these sizes, there is a P-2, which pipettes from 0.01uL to about 2uL for more precise measurements. It is important to know how to use a micropipette correctly, because measurement is key when it comes to research. When working with materials that can be easily contaminated, make sure you change tips each time to reduce cross contamination.

     The first thing to remember when learning how to use a micropipette is to hold it properly. Grip the pipette so that the ledge rests on your index finger, and you can press down the plunger with your thumb. Remember, the plunger is different from the tip eject button. If you press this one by accident, your tip will be pushed off the pipette. To adjust the volume you want to pipette, turn the black knob at the top so that it does not make a right angle. Then you can twist the plunger portion of the pipette, and you will see the numbers on the side change. This number indicates the amount of liquid you are pipetting. When you are done, twist the black knob back to lock the measurement. To pipette, push the plunger until you feel an initial stop (not all the way down), and then insert the tip into the liquid you wish to pipette. Let go of the plunger completely. Then push the plunger completely down to the last stop into whatever container you want the liquid in. That's all there is to it!

Safety Comes First

     The first pieces of equipment a researcher should familiarize himself or herself with is the safety equipment. Gloves, goggles, and lab coats are all required to maintain a safe working environment. Ethanol should be used to clean any surfaces that are going to be used. Know where the eye wash, emergency shower, fire extinguisher, fire blanket, and phone are, and how to work all of them. Make sure you know where biohazard containers are placed, and what goes in them (usually anything that contains DNA or possibly harmful material).

    http://www.dartmouth.edu/~chemlab/info/safety/equipment.html

     Most labs will have a designated area for gel electrophoresis, because of the use of ethidium bromide, a carcinogen. Anything used in this area should stay in this area to reduce contamination.

 





   
    Also, know how to use a Bunsen burner, and make sure it is turned on when you are working with bacteria, in order to keep the general area sterile.

 





     After you are done with an experiment, know how to clean up after yourself. Clean the surface you used with ethanol, and spray and beakers with alcanox, or bleach, if needed. Make sure all glassware is completely clean.

     Sometimes, biological waste is cleared using an autoclave. Know where the nearest autoclave is, and how to use it. Autoclaves function at high temperatures, so be sure to use the designated gloves when working with them.

     Well, there you have it! Lab safety in a nutshell.

The Research Process: An Introduction

     Research is the basis of all science, and the first step to any discovery. I will be covering drug-based discoveries in this blog. Throughout the year, I will experiment with a target protein, which I will determine later. More details on this target will be given, but the main purpose of this blog is to expose the reader to a research method and educate him or her about the scientific process.

     In order to begin research, the first thing that must be done is that the researcher must become familiar with the equipment he or she is working with, and should be able to perform several basic experiments without hesitation. This is an important step in the creation of a researcher, because without the basic understanding of how scientific equipment works, a researcher will not be able to understand the basis of his or her research.