What's new here?

Posts tagged ‘Biochemistry’

Biochemistry Classroom Kits

Part of the ‘side effects’ of the new electrophoresis sets we’ve added is that there need to be some classroom projects for teachers & students who want to use them. Well, when that happens next thing you know you’ve got all kinds of potential classroom labs to run! We’ve listed a few new biochemistry kits, some of them involve the electrophoresis apparatus, but others stand alone.

All of these kits are designed to handle sixteen students, operating in pairs. Activities take approximately 1 hour or two 1-hour sessions.

First up is the Properties of DNA Classroom Kit

In this lab, students will unravel Calf thymus DNA and spool it onto a glass rod. The materials provided include the DNA solution, and the materials to precipitate the DNA fibers. The DNA fibers can be up to 4cm long. The spooling is possible due to the double-helix nature of DNA. Students will learn about this and other properties of DNA. This classroom kit provides all materials except the very commonly available alcohol.The kit is just $104.95 and covers 16 students working in pairs.

Now the names might start to get a little long, as the next kit is Effects of Temperature on Cell Respiration

In this lab students use calibrated respirometers to measure the oxygen consumption and other factors in germinating grains. The exercise introduces students to a fundamental biological process and provides insight into seed structure and germination. This lab covers 16 students working in pairs. The kit costs $129.95 and includes the seeds and respirometers.

Taking advantage of the new Electrophoresis Apparatuses the next kits require the class have them available. The first kit is a simple, low cost Introduction to Electrophoresis

Costing just $47.95, this kit is a two-part lab where students identify unknown dye molecules by comparing their electrophoretic migration with the migration of known dyes. In the second part students identify dye molecules that bind to DNA and determine the mechanism. The exercise was designed for 8 groups of students and includes four colorful dye mixtures and DNA.

Hope you enjoyed that simple title, because next up is the impressively-named Specifity of Albumin Binding Classroom Kit, another lab involving electrophoresis equipment.

With this kit (no separate picture, sorry) we’ll just let the description speak for the kit:

“The binding of an enzyme to its substrate is only one example of the many specific molecular interactions that occur in biological systems. An analogous binding process occurs with serum albumin, which binds certain small molecular weight compounds and serves as a carrier molecule for these compounds in blood. In this exercise, students use an electrophoretic assay to examine the binding of various dyes to albumin. The results of this graphic analysis show that the binding of dyes to albumin is saturable, specific, compatible, and dependent on the native structure of the protein. The exercise is designed such that each of the eight groups of students performs a different experiment. Each group then describes their results and conclusion to the entire class. This exercise is a valuable experience in analyzing data and provides a fine introduction to enzyme kinetics. ”

OK, the final kit, which also uses Electrophoresis equipment, is a mouthful in the title alone: Electrophoretic and Chromatographic Analysis of Photosynthetic Pigments from Blue-Green Algae

Phew!

Again, we have to let the kit description do the talking:

“Cyanobactera, also known as blue-green algae, obtain their energy by photosynthesis using sunlight as their energy source. These organisms have been considered to be the oldest and the most important bacteria on the earth. It is believed that they were responsible for the initial oxygenation of the earth’s atmosphere through photosynthesis and it is also felt they were the precursors to the chloroplasts that are found in true algae and plants. There are two classes of photosynthetic pigments in Cyanobactera. The first class contains water-soluble proteins and the major protein is called Phycocyanin, which is blue. The other classes of photosynthetic pigments that include the carotinoids and chlorophylls are small molecular weight molecules and are insoluble in water but soluble in organic solvents such as alcohol. In this laboratory exercise, 8 groups of students isolate and characterize both groups of pigments. In part A of this exercise, students prepare a water-soluble extract from blue green algae and show that it contains the single major protein Phycocyanin by electrophoresis as shown in the gel below. They also determine the charge of this protein by comparing its electrophoretic mobility to the mobilities of dyes with known charges. In part B, they prepare an alcohol extract and analyze the smaller alcohol soluble pigments by thin layer chromatography in order to identify the chlorophylls and major carotenoid pigments. The results of this two-part study give students practical hands-on experience with isolation of components from cells as well as electrophoresis and thin layer chromatography and introduces them to one of the most important organisms on the earth. ”

Despite the long name and description, this kit also handles 16 students in pairs, and costs under $130!

These kits are excellent for schools or homeschooling groups efforts. They are economical and include excellent instructions. They are an excellent addition to any Biochem class’s curriculum.

Want to buy Classroom Biology Kits & Equipment?

www.spectrum-scientifics.com

Electrophoresis Kits – Part 2 Time for the Classroom.

So in part 1 we introduced you to the new line of Electrophoresis Apparatus for use in lab or classroom.

Trouble is, an Electrophoresis Apparatus doesn’t do very much on its own. There are actually accessories needed to get it operational, and that is why for labs that are just getting into Electrophoresis. Some things, like the Agarose, is a consumable. Other items, such as the power supply, and a pipettor are crucial to electrophoresis. So several kits have been assembled to get all the hardware in place.

First is the EL-100 Demonstration Kit, this includes a EL-100 Electrophoresis Apparatus, Power Supply, Adjustable Volume Pipettor, and an Experiment Kit: Introduction to Electrophoresis

Parts not shown: Pipettor, Power Supply, Experiment Kit.

For more serious work in the classroom, a classroom kit has been set up using the EL-600 Apparatus with its 6 gel trays – This classroom kit comes with two pipettors (50ul) 2 racks of pipettor tips, power supply and EL-600 Apparatus:

For full classroom experimentation, more than a single Electrophoresis Apparatus will be required, for that there are two stations set up to handle groups of 16 (dual Station) or 32 students (Four Stations).

The Dual stations come using either the EL-100 (each with single 7cm x 14cm trays) or EL-200 (with two 7cm x 7cm trays per apparatus).

The Dual stations include two electrophoresis apparatuses, a power supply, and 2 adjustable volume pipettors:

The Dual Station El-1oo and Dual Station El-200 can support up 16 students

The Four Station Electrophoresis Kits also come with the EL-100 or the EL-200

The Four Station Kits include 4 of the appropriate electrophoresis apparatuses, 2 power supplies, and 4 adjustable volume pipettors.

In part 3, we will discuss the classroom kits available.

Want to buy Electrophoresis & Biology Classroom equipment?

www.spectrum-scientifics.com

Spectrum Scientifics Microscope Buyer’s Guide – Repost

Things are still quite hectic in the store  so this is great time to repost our Microscope buyer’s guide. This is the time of year when many a budding biologist gets their first microscope!

 

Spectrum Scientifics Microscope Buyers Guide

Congratulations! You’ve decided to buy a microscope! A microscope is a wonderful instrument that can fascinate kids and adults alike. With proper care, a microscope can last a lifetime. But buying a microscope can be confusing for the first time buyer. There are so many different designs, it can be a bit overwhelming. This guide should help you make the proper choice in deciding on a microscope model.

First let’s start by discussing the different designs of microscope. We will break microscopes into three different categories: Compound Microscopes , Inspection/Dissection Microscopes, and ‘Other’. We’ll cover these one by one.

Compound/Biological Microscopes : Compound (or Biological) microscopes are the models designed to be used with slides. They are high Compund/Biological Microscopepowered; using multiple objective lenses (the lenses that point at the slide) to typically provide 40X, 100X, 400X and sometimes 1000X right off the shelf. Modern compound microscopes usually have some sort of illumination from below to light up the slide. Depending on the design of the compound microscope it may have features like binocular eyepieces (two eyepieces, but do not provide stereo vision) a mechanical stage for moving the slide easily, coarse and fine focus (for easy focusing) and different lighting designs.

The disadvantage of a compound microscope is that you pretty much must use it with slides. You can’t just plop a bug, coin, or plant leaf onto the microscope and expect to get a decent image. Compounds aren’t designed to do that. You can cut up the leaf/bug/whatever and make it into a slide with some effort and a slide-making kit, but that does take some time and only lets you view s small part of the the found object.

Inspection/Dissection Microscopes: Inspection/Dissection Inspection/Dissection Microscopemicroscopes are designed to be used with any object you can fit on the microscope’s staging area. This can be coins, stamps, bugs, plant parts, circuit boards, small animals, or whatever else you might find. Inspection Microscopes often have much lower magnification (10x-40x is typical), much wider viewing fields, and very often the binocular versions give true stereo vision. This allows the viewer to ‘work’ (I.e. dissect) on the object being viewed and get a true sense of depth of objects like coins. Inspection Microscopes may have only 1-2 levels of magnification verses the 3-4 on compound microscopes. The microscope will also have top-down lighting, and some may have bottom-up lighting as well. The eyepieces used in many mid-range inspection microscopes are often larger and more comfortable to use.

The disadvantage of a compound microscope is that its magnification is very low and you cannot use it with slides. That means if you want to see cells, bacteria, or other very tiny objects you will need to get a compound microscope as well.

As you can tell from these write-ups, these two designs are very different from each other. Before we discuss the third category, let’s compare and contrast these two designs:

Features: Compound Microscopes vs. Inspection/Dissection Microscopes

Compound Inspection/Dissection
Magnification High: 40x and up Low: 10-40x typical
Levels of Magnification 3, sometimes 4 (40x, 100x 400x typical) 1 or 2*
Lighting From Bottom From top (or top and bottom)
Viewing Monocular or Binocular, but not true stereo Stereo Binocular
Viewable Objects Slides Coins, stamps, bugs, plants, circuit boards, etc.
Extra Features (depends on model) Mechanical Stage, Coarse & Fine Focus, Bottom light
    *Some models of Inspection Microscope have a continuous zoom from 10x to 30 or 40x

This chart should give you some idea of the basic comparison.

We haven’t forgotten about the third category of microscope: Other. This category covers some odd designs that work as specialty instruments. Some examples of Other microscopes would be:

Hand-Held Microscope: These are small, pocket-sized microscopes used Hand Microscopein a fashion similar to Inspection/Dissection microscopes. They may have higher magnification than Inspection microscopes (30-100x power), often have a built in light, and are light and portable. Their main disadvantage is they have a limited viewing field- you must put the scope directly on the object being viewed. Their optics & lighting are also rarely up to the quality of full-sized microscopes, and moving to find a specific part of an object can be tricky. Still they are great in the field where a full-size microscope would be unwieldy.

Digital Microscopes: Many traditional microscopes can have a digital Digital Microscopecamera built into their structure, or can have their eyepiece replaced with a digital camera. But some microscopes are designed from the ground up to be used as high-power digital microscopes. These items have no eyepiece, only a CCD camera and an objective lens. They may have fixed or variable magnification, and the computer screen resolution will vary from model to model. Many ‘toy’-like designs have VGA quality graphics, which is 480 x 640. This level of quality is acceptable for kid’s use but is not sufficiently detail for any real work or study. Usually 1.3 Megapixels is the highest quality available for devoted consumer digital microscopes. If you desire higher resolution a compound microscope with a digital microscope eyepiece might be in order.

High Power Magnifiers: A hand-held magnifier is a very different 10X Triplet Magnifierinstrument from a microscope, seeing as how most magnifiers have about 2-3x magnification and microscopes can go as high as 1000x. But some close work magnifiers have very high power (10x and up) and the line between a microscope and a magnifier starts to get blurred. As far as optical design goes, they are still very different animals: The magnifier has just one lens (or set of cemented lenses) while the microscope has both an objective and eyepiece lens. Although the difference is there, the jobs they cover get blurred. If you need a lower powered microscope or a high power magnifier, make certain you are choosing the correct tool for your viewing needs.

Hybrid Microscopes: Given the difference in use between a compound and an inspection microscope it didn’t take to long for some folks to come up with a design that tries to do the job of both microscopes. Usually this is done by taking a compound microscope design and adding a top-down light to the system. These designs can be a great boon to parents or buyers who cannot decide which usage they would prefer. The disadvantage is that like many other things that try to do multiple jobs, they are not the best at either job. Most often hybrid microscopes are better at being a compound microscope than an inspection microscope (mostly due to the higher powers of a compound microscope), but at least the option for using the microscope both ways is available. Consider a hybrid if you can’t decide between designs, but remember it won’t do the job as well as a devoted microscope.

Toy Microscopes: Many ‘toy’ microscopes are available on the market, usually they are either plastic hand-held models or plastic versions of compound designs. The former can be great fun for small children who would like to have something to view nature close-up but can still handle their not-always-delicate hands. The latter, however, is usually to be avoided. Cheap plastic bodies and cheap plastic lenses will give the viewer a very poor experience indeed. Companies that make these items often pile on junk accessories like plastic ‘viewers’, poor slide making accessories, and other gimmicks to cover the fact that the instrument is junk. Avoid these if at all possible.

OTHER THINGS TO CONSIDER

So now that we’ve discussed the various microscope designs, we should talk about that are features of microscopes:

DIN Objectives: DIN stands for Deutsches Institut für Normung – Don’t worry about that. Just understand that DIN eyepieces are set to a higher standard the the average beginner microscope. DIN objectives are generally universal so you can take one DIN objective out of one microscope and thread it into another. DIN eyepieces are often a bit more costly.

Digital Microscope Eyepieces: Digital eyepieces can be a great boon to Digital Microscope Eyepieceyour viewing experience. When plugged into a computer they can be used to view objects on a much larger screen, and the images can be saved, modified, emailed, etc. Some digital eyepieces can make movies as well. Some microscopes have digital eyepieces built into the body of the microscope, but almost all non-toy microscopes can have their eyepiece’s removed and replaced with a digital microscope eyepiece. The image quality from a digital microscope eyepiece can go from VGA (or even TV) quality all the way up to 5.0 Megapixels or even more.

ACCESSORIES:

One nice feature about microscopes is that they don’t need a whole lot of accessories to get a good experience. But there are a few things you can get to increase your viewing experience:

Prepared Slides: Professionally made slides are always excellent to have around. They let you see objects with a quality that few can match. They also may be of specimens that may be very hard to obtain. Consider having a few prepared slides to enjoy.

Slide Making Kits: Sooner or later you will want to make your own slides. This will involve blank slides, coverslips, a razor (for cutting samples) and some mounting medium. These can be bought individually, but it is often more economical and convenient to buy a kit.

Special Slides: Blank slides with concave dips can be obtained for holding liquid samples. This is excellent for examining microscopic life in pond water and other sources.

Slide Boxes: Once you make your own slides you should store them properly in a slide box. Don’t leave them to get dust and scratches.

Microtome: If you make a lot of slides, cutting thin sample sections with a razor can get annoying after a while. A microtome can help. It is a mechanical device that helps cut a thin sliver off the sample. Think of them as working like the meat slicer at your deli only on a much smaller scale. Microtomes can be hand driven devices for around $75 to fancy automated item costing hundreds or even thousands of dollars.

CONCLUSIONS:

As mentioned above, before you decide on what model microscope you want, make sure you know what it is you want to do with it! Fun can be had viewing both prepared slides and making your own slides using a compound microscope. But it can also be a real thrill to take objects straight from the backyard, or even from your pockets and put them under an Inspection/Dissection microscope. If you have needs beyond having fun observing (research, coin collecting, etc), make certain that your microscope does that sort of job first and foremost.

Happy viewing!