This article is based on material originally published in Illustrated Guide to Home Chemistry Experiments: All Lab, No Lecture, by Robert Bruce Thompson, and the not-yet-published Illustrated Guide to Forensics Investigations: Uncover Evidence in Your Home, Lab, or Basement, by Robert Bruce Thompson and Barbara Fritchman Thompson.
Scientists have a long history of making do with whatever equipment is readily available or easily constructed. (Home scientists’ spouses and parents get used to household objects mysteriously disappearing, but that’s another story.) Most common lab glassware items — test tubes, beakers, flasks, and so on — were invented by chemists to replace the household items they’d been using. For example, while he was working as lab assistant to the great English chemist Humphry Davy, Michael Faraday invented the test tube. Before then, many chemists used champagne glasses as test vessels…and their spouses probably wondered where all the champagne glasses had gone.
These days, things are even easier for the scientist-scrounger than they were a century or two ago. We have treasures they could only dream about, including cheap, heat-resistant Pyrex kitchen measuring cups, disposable soda bottles made of chemical-resistant plastic, cheap filter paper and chromatography paper (bleached paper coffee filters), inexpensive hotplates, and so on. In fact, you can get a good start on equipping a home science lab using items from Wal*Mart, Home Depot, or similar retailers.
But doing real science at home requires some specialty items that are difficult or impossible to substitute. My editors at MAKE asked me to make a list of essential specialty lab equipment that every home scientist needs as a “starter kit” to perform a wide variety of experiments in chemistry and the other sciences. So I sat down to think about which items would provide the most bang for the buck. Here’s what I came up with:
- Goggles – Although you can buy protective goggles at any hardware store, they are intended to protect against particle impact hazards, not chemical splashes. So, as the first and most important item, you need to purchase laboratory-rated chemical splash goggles.
- Test tubes and accessories – It’s hard to imagine a science laboratory without test tubes. They have dozens of uses, from running small-scale reactions to storing solutions or specimens to generating or capturing small volumes of gases. A half dozen test tubes is a good starting point. You’ll also need various accessories: a test tube rack, test tube tongs, and a test tube brush. Buy at least one solid and one one-hole rubber stoppers to fit your tubes
- Beakers – Although you can sometimes substitute other containers, every home science lab needs at least one or two real beakers, if only for heating solutions. The most useful sizes for a home science lab are 150 mL and 250 mL.
- Flask – An Erlenmeyer (conical) flask has many uses around the lab. The most useful size for a home lab is 250 mL. You’ll also want a two-hole rubber stopper to allow the flask to be used as a distillation vessel or gas-generating bottle.
- Graduated cylinders – Graduated cylinders are essential for measuring liquids accurately. The most useful sizes for a home science lab are 10 mL and 100 mL.
- Alcohol burner and burner stand – Although liquids in a beaker or flask can be heated safely on an electric hotplate or kitchen stove burner, there are times when the higher temperature of a flame-based heat source is needed. An alcohol burner has been the traditional heat source in home labs for more than a century, and it remains a good choice today. Buy a modern safety alcohol burner as well as a burner stand to support the vessel being heated.
- Thermometer – A good lab thermometer is essential for any lab work that involves thermochemistry or calorimetry, and is often needed for simple procedures such as distillations, making up solutions, or managing a reaction.
- Polyethylene pipettes – These beral-type pipettes are made of chemical-resistant plastic, and can be re-used over and over simply by rinsing them thoroughly after each use. In addition to their obvious use for transferring liquids, these pipettes can be calibrated volumetrically (with a graduated cylinder) or gravimetrically (with a balance) and then used dropwise to transfer measured liquid volumes very accurately. With scissors, you can convert one of these pipettes into a small chemical scoop or a small filtering funnel. Buy a pack of five or ten pipettes.
- Reaction plate – A reaction plate is a rectangular chemical-resistant plastic vessel with an array of small wells. It’s ideal for testing one or several specimens against one or several reagents, and because it uses much smaller volumes than test tubes, it helps economize on expensive chemicals. Cleanup is also a lot faster if you have only one dirty reaction plate instead of many dirty test tubes. Buy one of the 24-well polystyrene models with a lid. Be careful using it with organic solvents, which can damage it.
- pH test paper – It’s often important to test the acidity or basicity of a solution. The old fashioned answer in home labs was using litmus paper, which provides only a general indication of acidity or basicity. Rather than litmus paper, you should buy a vial of pH test paper that allows you to determine a numeric value for the actual pH of a solution.
- Small accessories – You’ll also want various small useful items: a funnel, stirring rod, glass tubing, heat-resistant flexible tubing, and a Mohr pinchcock.
We suggest you buy high-quality student-grade equipment rather than professional grade. The student grade is perfectly acceptable for home use, and costs much less. Don’t make the mistake of paying too little, though. There’s some real garbage out there, and it’s cheap in every sense of the word.
For example, a professional-grade Pyrex or Kimax beaker might cost $5. A similar beaker from one of the good brand-name Asian manufacturers (Bomex, Borosil, or Premiere) might cost $2.50. A no-name Chinese-made beaker might sell for $1.50. As our friend and technical adviser Dr. Paul Jones put it, if you subject 100 of the Pyrex or Kimax beakers to a strong direct flame, one of them might shatter. If you do the same with 100 Bomex, Borosil, or Premiere beakers, two of them might shatter. If you do the same with the no-name Chinese-made beakers, all of them might shatter.
You can buy the items you need individually or as part of kits sold by most lab equipment suppliers. Maker Shed offers a basic kit that includes the items mentioned in this article, as well as a few other kits that supplement the basic kit.
August 19, 2009