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Archive for July, 2012

New Hot Plate & Magnetic Stirrers – Analog & Digital

There’s a couple of new players in the almost-obligatory-in-labs Hot Plate & Magnetic Stirrer combo unit. The new United Scientific Analog and Digital Models.

First up the Analog unit:

This hot plate/stirrer unit has a stainless steel plate with double PT sensors. Control is by two dials, one for heat and one for stirring. It can spin a stir bar from 50 to 1700 rpm and has a maximum temperature of 350 degrees C.

The digital hot plate/stirrer has even more features:

This hot plate/stirrer has a scratchproof chemically resistant coated ceramic plate. It has 1-dial control for temperature, time and speed.  Each of these has its own LED readout. The unit can spin from 50 to 1500 rpm and can heat up to 350 degrees Celsius.  The unit also features a pole with mounted temperature probe so accurate readings can be taken and the unit can shut off before a set temperature is exceeded. This feature frees up lab workers to do other things as they need not constantly monitor the temperature of the liquid. The pole system also allows the temperature to be read during vigorous stirring.
Both stirrers are ready for sale and will ship straight to your home or office.

Link to: Analog Hot Plate/Magnetic Stirrer ($279)

Link to: Digital Hot Plate/Magnetic Stirrer ($449)



Astronomy Hints #16 Reflector vs. Refractor

This astronomy hints post is going to double cover much of what we covered in our Telescope buyer’s guide but we hope to go into a bit more detail for those considering their first telescope – and that is the raging battle between reflectors (telescopes that use mirrors) and refractors (telescopes that use lenses).

Now we are just concentrating on the telescope’s optical tubes. We won’t talk too much about mounts right now. First let’s take a look at the two designs:


Now odds are, if you are looking at these two designs and don’t know a thing about telescopes beyond what TV & movies may show your first instinct will probably be to think of the refractor (the one on the left) as being what you think of as a telescope: a tube pointing at what you want to look at while on the opposite end of the tube is the place you look into. Its very simple, and very intuitive. It even invokes the old brass collapsing telescopes every pirate move seems to be require to show by law.

Conversely, the reflector (on the right) can be a bit odd-looking. First of all, the front end is open and empty! You have to look all down the tube to see any sort of optics 013thumb(i.e the primary mirror).  Then you notice that there is no place to look through at the end of the tube. The eyepiece just kind of sticks out of the side, and the finderscope (a little telescope used to help find things in the night sky) isn’t in the same place as the refractor. What is going on here?

Well, what is going on is that while the result is the same (light gathering and magnification), and some of the fundamental optics are doing the same thing, the fact is they are both doing it very differently.
First up the refractor employs a large lens, located at the front of the tube, to refract (hence the name) or bend the light. This bent light is designed to come to form an image very close to where the eyepiece is located (you can get an idea of how this works by making an image of an object on a wall with a magnifying lens – just remember the telescope is designed to have the image form much further away!). The eyepiece then focuses on this image. In a way this is like having a magnifying glass focus on a magnified image – sort of.

Diagram of a Refracting Telescope

Conversely, the reflecting telescope doesn’t bend the light, it reflects it, or bounces it if you prefer. This is similar to what the mirror on your car or in the bathroom does, except that the mirror in a telescope is curved. So it also forms an image not very far from the telescope’s eyepiece:

Reflector Telescope Diagram.

So now that you know how each is different, the question becomes:


The fact is: There is no simple answer for this. Let’s just go over some basics.

Let’s start with the advantages



  • Tend to have sharper images
  • Have more traditional designs
  • Do not require much maintenance or collimation


  • Are less expensive to build at larger sizes

Seems like Refractors are the winner, yes? No, not really.  You see that first advantage of reflectors is a killer. It is simply much easier to make a larger mirror than a large lens for a telescope. With a mirror, you need to polish only one side and coat it. With a reflector, you need to polish both sides at least two lenses (most refracting telescopes use air-spaced achromats (multiple lenses) and will probably need coat them with an anti-reflection coating as well.  That’s four lens sides, each one with a different curve.

The major selling point of refractors at small sizes is their traditional designs & lack of need for collimation. A small refractor will cost about as much as a small reflector and will give a beginning astronomer fewer things to worry about. The other advantage, the sharper images,  tends to only come with higher-quality refractors or even what are known as apochromatic (3 or more lenses, or two very well designed ones) objective lenses. These can get very expensive, but at small sizes (i.e. easy to transport) the refractors can easily win out with image quality. Many astronomers, not wanting to haul around heavy reflectors, may opt for these advanced refractors.

Let’s look at the other side of the coin:



  • “Chromatic Abberation” – where the lens breaks up the light like a prism
  • More expensive than reflectors at mid and large sizes.


  • Requires occasional maintenance/collimation for ideal viewing
  • “Secondary Shadow” from secondary mirror will cause some loss in the light gathering

Chromatic Abberation can be annoying when viewing bright objects (the Moon, Jupiter, Venus, etc) as it results in what is known as a “violet fringe” around the object. This can be filtered out, and it doesn’t show up much on dim objects (light galaxies, nebulea, etc.) . But it can be frustrating to some novice viewers.  More critical to refractors is the expense of making medium and large-sized models. We already covered why in the advantages section.

Reflectors on the other hand have the problem with collimation. Most large reflectors are probably going to need collimation if they’ve been moved around a lot. They will still work if they aren’t precisely collimated, but the images will appear streaky. Collimation can be a bit tricky to master and so can frustrate novice astronomers.

The secondary issue is bit of a misnomer. What it essentially says is that any reflector telescope is not going to gather as much light as its full surface area as a portion of it will always be in the shadow of the secondary mirror. This is mostly just a nuisance as if one needs more light gathering power one simply makes a larger primary mirror., but then weight does become an issue.
So to answer the question of ‘which is better’, there really isn’t much of a straight answer – at small sizes (for beginners)  there is little reason to not get a refractor. But once the sizes get larger the reflector very quickly becomes much more economical. These rules are in no way ‘hard and fast’ as there are many exceptions to them. But as an overall guide they can give you an idea of what design to look at.


BuckyBalls To Be Banned?

BuckyBalls have been a best selling desktop toy since we added them over three years ago.  A bunch of spherical high-power magnets the stick together well, but can be manipulated like silly putty or made into all kinds of cool shapes.

BuckyBalls have had their struggles over that time: The biggest issue it seemed was the skyrocketing price of rare-earth neodymium used to make the Buckyballs. But it seems they were causing injuries to children too. Not the very young kids you might expect, but kids in their tween/early teen years. It seems that some kids were using the BuckyBalls to make fake tongue stud or other piercings and swallowing them. Now this might be dumb already, but then you have to consider that swallowing just one BuckyBall isn’t going to be a problem (as long as you stay away from MRI machines. You have to swallow two or more. Then they attract each other in different parts of your intestinal tract and pinch them together the intestines and cause health problems.  To date, 2 million sets of BuckyBalls have been sold, with approximately 1 dozen incidents (another dozen have been attributed to other magnets toys) that required surgery. No deaths have been caused by BuckyBalls.

The Consumer Product Safety Commission moved yesterday to ban BuckyBalls due to these cases. Despite BuckyBalls’ makers Maxfield & Oberon making efforts to prevent young  children from being sold BuckyBalls (extra packaging, voluntary recall). CEO Craig Zucker has blasted to arbitrary and unfair nature of the suit, stating “”I don’t understand how and why they did this without following their own rules before allowing us to make our case. It almost seems like they simply wanted to put our products and industry out of business.”

It should be noted that CPSC has asked M&O to cease selling BuckyBalls, which is a bit like asking Ford to stop selling cars. CPSC has also targeted BuckyCubes, a product with a cube shape instead of spherical for the same reasons as BuckyBalls, despite there being no incidents with BuckyCubes and a much lower likelihood of any such incidents due to them not resembling tongue studs. In essence, the CPSC has asked M&O to go out of business.

Stay tuned to see how this turns out.

UPDATE: Maxfield & Oberon has struck back with this reply: https://www.getbuckyballs.com/buckyballs-only-marketed-to-adults-cpsc-press-release/

Sally Ride, First female US astronaut, RIP.

Yesterday, Sally Ride, the first female US astronaut, and third woman in space overall, died after a long fight against pancreatic cancer.


Sally Ride was not the first woman in space, and she was not even the second woman in space.  Valentina Tereshka was trained in a crash course (she was a parachuter but not a pilot) and her flight was considered more of a stunt than anything else – mind you this was the era of public space stunts by the superpowers – but the lack of training and the superficial  nature of the her flight was indicative of the ‘propaganda over progress’  nature of USSR space flights that led to them to fall behind the US program. Svetlana Savitskaya was a more fully trained astronaut, but her training had started in 1980, wheras Sally Ride had been part of NASA’s astronaut program since 1978.
Sally Ride faced a higher level of scrutiny from the media due to her gender. While NASA was well past the age of  ‘male, clean-cut types only’, there was still a degree of chauvinism displayed. Sally Ride was asked once if she cried when things went wrong, some wondered if the space flight would damage her reproductive organs, some less-than-stellar experts claimed her hair (done in an 80’s style perm) would destroy everything inside the shuttle, and the question of how she would go to the bathroom in the shuttle was asked- a lot. Although to be fair ‘how do astronauts go to the bathroom in space’  is the most commonly asked question of the astronaut program, male or female.  Ride answered most questions skillfully,but pointed out the double-standard by asking “how come Rick (Hauck) doesn’t get these questions?”, and just outright not answering a couple of others.

Ride flew twice on the Space Shuttle, on flights STS-7 and STS-41-G. She also acted as the ground-based Capsule Commander for the 2nd and 3rd Shuttle flights. When disaster struck the Challenger in 1986 she was on the investigation team.  Even though she left NASA in 1987, she was asked back to help the accident investigation of the 2003 Columbia space shuttle disaster.

Once Ride left NASA, she continued to keep most of her life private while working for private companies. She acted as an inspiration to young girls in science but never pressed the issue very far – accepting her duty as a role model. But she considered herself a scientists & astronaut, not a celebrity.  She rarely exploited her fame – (a commercial for Office Depot was about it).

Sally Ride was 61.



Tie-Dye Lab Coats

OK, we’ve carried lab clothing before – protective aprons, protective sleeves, etc. But let’s face it – they aren’t exactly exciting:


But now there is something that will add a little spice to the labroom. We now have Tie-Dye Lab Coats!

These lab coats are 100% cotton and are colored in a vibrant tie-dye pattern! The sizes are Small (S), Medium (M), Large (L), Extra-Large (XL), and Extra-Extra-Large (XXL)

Coats feature one upper breast pocket, two roomy lower pockets, side slit openings, and an adjustable back belt.

Add some color to the lab, and get yourself a tie-dye lab coat today!

Mars Science Laboratory AKA Curiosity – The Landing

As of this writing, the Mars Science Laboratory is scheduled to make landfall in less than 19 days (clock countdown here).  The Mars Science Laboratory, nicknamed Curiosity, is one of the biggest rovers to go to Mars, measuring at 10 feet long (often compared to a Mini-Cooper in size). Only the Viking Lander was comparable in size and that didn’t move or do anywhere near as much as Curiosity will.

Since Curiosity is a bit of a bear, it is going to be delivered in what we consider to be the coolest method of landing a roving Mars vehicle ever:


Look like fun? The lander will need to go from 13,000 mph to zero in under 7 minutes. Sound like real fun? Well if youhave an XBOX360 and XBOX account you can actually play a Curiosity  landing game designed by NASA. It is free, just look up “Mars Rover Landing” on XBOX live. It even works with the Kinect.

Curiosity is full of equipment,that mast has a camera that covers a large portion of the spectrum, so it can see in Infrared and Ultraviolet. The camera has several filters and modes to get the best imaging. Curiosity also carries a Spectrometer, Robot Arms (with cameras), Sample analysis equipment, and much more.

Curiosity is scheduled to land on August 5th or 6th depending on your position on the planet.




New Hands-On Science Books

There’s some new books in town, and they are all great fun for kids. They involve hands-on science projects on a  variety of topics.

First up is the Flying Machine Book:

This books has instructions on how to build 35 different kinds of homemade rockets, gliders, helicopters and more. Soda-Pop rockets, paper boomerangs, rubber-band  powered gliders are all part of the of this 197 page book of flying fun!

Next up is the Amazing Rubber Band Cars

This book does one thing: Have kids make cars powered by rubber bands – but it does it sooo well. Kids will learn about axles, gears, pulleys, friction, tension, speed, and much more as they build a dozen rubber band powered cars out of simple materials like cardboard, pencils, old CD’s and of course rubber bands.

The Paper Boomerang Book takes a part of that first book (The Flying Machine Book) and expands on it dramatically:

Instead of just a couple of pages on boomerangs, this book goes into heavy detail on how to build working paper boomerangs! You start by building trainers and work up to distance models, etc. Chapters are devoted to boomerang theory, tweaking techniques, decoration, and throwing styles!


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


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?


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?


NEW: Walter Electrophoresis Kits Part 1

Electrophoresis is a process used in forensic labs and other biology labs. It works by placing DNA material in a gel next to comparison samples and controls and applying current to the gel. The shorter molecules move further than the longer molecules through the gel like it was a sieve. Proteins can be sorted out and dyes are used to show the position of the material’s movement. You might have seen some photos of the results if you ever watch a courtroom video where forensic DNA is involved. Often the lawyer or forensic scientist is shown pointing at a acetate sheet with short lines at various intervals. This is an example of electrophoresis results.

So electrophoresis is cool! But you can’t just get some gel and plug it in. You really need an apparatus to do electrophoresis, and they can often be very costly.

But now we have several new electrophoresis apparatuses (appartati?) available. These are excellent for basic classroom work, from High School to College. They are also good for labs as well.

The primary apparatus is the EL-600 Electrophoresis Apparatus

The EL-600 holds 6 7cm x 7cm casting trays, each with a 6 Tooth Comb for making the needed indentations in the gel. (The comb is left in the casting tray when the gel is poured, then the comb is removed leaving divots for the samples to be inserted with minimal disturbance to the gel.

The pieces of the apparatus, which applies to all the Walter Electrophoresis Apparatuses are made of thick acrylic, making it durable and leak-proof. The chamber is UV transparent and includes two knobs at both ends which can be pressed down to assist in easy removal of the lid while minimizing the movement of the unit.  The power knobs connection jacks are marked positive and negative and will not allow the cover to fit if the incorrect lead is on or the lead is on incorrectly. The trays are also marked with positive and negative ends.

The EL-600 is the flagship of this new electrophoresis apparatus line, but for those who need a unit for small classroom work there are the El-100 and EL-200 .

EL-100 Electrophoresis Apparatus

EL-200 Electrophoresis Apparatus

The EL-100 and EL-200 are essentially the same apparatus, but the EL-100 has a single 7cm x 14cm casting tray while the EL-200 has two 7cm x 7cm casting trays, and two combs to boot.

All these Electrophoresis Kits do require a power supply to operate, either with 75V or 150V. Many labs may already have a power supply available, but in case they do not a power supply is also available:

Power Supply

Now to make the gel, you need Agarose to make the gel, typically 1gm of Agarose is used to make 100ml of gel. Fortunately we have BenchMark Scientific as a supplier of Agarose in 25ml, 100ml and 500ml jars:


Next up in part 2: The classroom and demonstration electrophoresis kits.

Want to purchase Electrophoresis & Biology Equipment for your classroom?