Making permanent slides is a process that requires some preparation and some practice! Now that you have had some practice using kitchen powders such as flour, baking powder, cake mix, pancake mix, instant pudding, salt sugar and whatever else you could find its time to make some slides that you can use as a reference and share with others. Permanent slides are just that…permanent. They can not be disassembled once they are made. Semi-permanent slides are made to last a few hours or as long as your work session at the microscope. For semi-permanent slides olive oil is a good choice to begin with because it is readily available and non-toxic. Water is a good choice for biological materials and for items that are not soluble in water. The eraser end of a pencil can be used to gently disperse your sample between coverslip and slide by pressing on the coverslip (after adding the oil and the particles) and moving the coverslip using the eraser to grip the coverslip. A side to side or circular motion works well. Be careful with hard particles as too much pressure could break the coverslip. Practice using the olive oil and a few samples before starting permanent mounts. For permanent mounts I recommend Norland optical adhesive either #63 or #68. Store the bottle inverted as this will help minimize any air bubbles that may form. Start simple…pollen, flour, something that will disperse easily. One small drop on a glass slide, add your particles, break up any air bubbles with a clean toothpick, add the coverslip and allow the adhesive to flow. Pressing slightly with your pencil eraser will speed up the process. Cure for about 10 minutes with a blacklight (long wave UV). The adhesive will continue to cure after exposure to the blacklight so the slides should be “cured in 24 hours”. If not, more blacklight exposure. Please read all cautions and safety warnings that apply when using long wave UV. Do not use a short wave UV source as this can damage your eyes!! A good price for microscope slides is an inexpensive one..Grafco slides Coverslips can be found too…coverslips. I have not purchased from this place but the price looks good! Have fun and remember to dispose of glass properly and leave a clean work space for the next person.From GMS slide kit…thanks to all who volunteered to put these together!!
Archive for the ‘Tips & Tricks’ Category
We had a great workshop at the new Gwinnett Tech Bioscience facility. Thank-you Dr. Gibson, Jenny and everyone for your time and energy! The first part of the morning I gave a brief description of how MVA Scientific Consultants used light and electron microscopy to solve problems that deal with particles, dusts and other materials that can only be characterized and identified with a microscope…they are simply to small to be examined any other way. After a short break, we took the covers off of the (brand new) compound microscopes that were in the lab and proceeded to learn what proper illumination is and why it is so important. Proper illumination is important to obtain full resolution, a misaligned microscope can not be used to image the fine structures that define small particles. Remember to have a slide available to start with. Focus on the slide using a 10X or lower magnification objective. Adjust the interpupillary distance for your eyes if you are using a binocular microscope. Adjust the ocular focus, one eye at a time so that each eye is focused on the same object on the slide. If your microscope has a condenser, close the field diaphragm, center and focus the image of the field diaphragm in the field of view. Repeat with the next highest power objective. You should have a decent image at this point. Preparing your own temporary slides is easy….you need glass microscope slides, glass coverslips, water, olive oil, toothpicks and samples to mount for examination. The technique for imaging with a transmitted light microscope applies to object that are transparent…many powders, soils, sands and kitchen ingredients can be viewed with the light microscope with a little practice. Add a drop of olive oil (refractive index @ 1.47) to the center of the microscope slide. Touch your sample (plenty of pollen around right now!) with the toothpick and scoop a small amount of sample (less is more). Mix the sample into the oil and cover with the coverslip. Focus at 10X (or lower) magnification and enjoy the view! More later….
Micro-aquariums are made with clear silicone, 75mm X 50mm glass slides and a 75mm X 25mm glass slide cut in half for use as a spacer. Place a thin bead of clear silicone on three sides at the edge of one of the 75mm x 50mm slides. Place the 2 half slides (stacked as a spacer “2 slides thick”) on the glass slide that now has a silicone bead being careful not to disturb the silicone. Carefully place the second 75mm X 50mm slide on top of the 75mm X 50mm slide with the silicone bead. Carefully align the slides and clamp with a large paper binder. Clamp on the area containing the half slides so as to not crack the aquarium! Add additional silicone to the rim of the glass “sandwich” until there are no gaps. Let set for 24 hours. Remove paper binder, half slides (spacers) and trim off excess silicone with a razor. Add pond water with a plastic pipette and seal with a snug fitting rubber band. Examine with a hand lens or stereomicroscope. Carolina biological supply sells them for $6.50 each if you want to avoid the labor.
Microscopy classes and literature: McCrone Research Institute
For the improper way to clean microscope lenses and objectives…never use a metal object to clean a lens!!! NEVER DO THIS!!!
NEVER DO THIS!