Stem equipment and supplies

[Show a picture of our storage wall]

Our school, the Las Cruces Academy, has a huge array of scientific equipment and supplies. It’s the result of my childhood experiments that led me to become a scientist, plus 50 years of research and teaching at Yale, Los Alamos National Labs, New Mexico State University, some overseas posts, and now 13 years of teaching at the Academy. Add to that the research and teaching career of my wife, Dr. Lou Ellen Kay, founder of the Academy, and donations from other, especially the late Dr. Will Beattie, who made a second career after Los Alamos doing scientific demonstrations in schools.

Much of the equipment I list is available from multiple suppliers. will almost always show up in an online search for an item, but I refuse to buy from them, based on Amazon’s treatment of its workers and its gobbling up the business of the smaller suppliers. Make your own ethical decisions.

The lists here are very extensive, from multiple levels of science. Most school labs will have a fraction of these items. I list them all here as food for thought, about what demos and experiments you might consider. There are things I am missing, too, from other useful demos and experiments; send me any suggestions!

A very good supplier for almost all fields of science – especially biology and chemistry – is Carolina Biological Supply, at The prices are good, as is the service. There are many other suppliers for various fields of science and technology. Here are some key ones that we’ve used: – for absolutely anything in electronics and electrical goodies – similar – not quite as quick as DigiKey

Jameco Electronics – for electronics kits and some components

B&H Photovideo – – for cameras of all types, optical filters, audio equipment – the gold standard for price, selection, and service!

Davis Instruments – for weather stations and sensors and – for Raspberry Pi computers and accessories – for chemical elements at great prices

Fisher Scientific – and – bell jar (vacuum chamber) – for sodium metal and other neat things chemical

Omega Engineering – – for all manner of electronic instrumentation – for Geiger counter kits and uranium ore samples

Sigma Aldrich – for some chemicals (more expensive for most than is Carolina Biological Supply)

Your local grocery and drug store, for many common chemicals such as hydrogen peroxide (go to a hair salon for the stronger stuff!), bleach, a glucose meter, dry ice, etc.

Your local welding supply store for liquid nitrogen, graphite electrodes

Your local Batteries Plus Bulbs for batteries, lamps, and expertise

Your local electronics parts place – in Las Cruces, Edgar Digital had scads of integrated circuit chips, a huge capacitor, and many odds and ends; alas, Radio Shack is out of the real parts business for some really out of the way items!

Note: Highlighted items are links to demos or experiments that have been posted (or will be posted)

Really useful, general-purpose items

One significant investment: a rolling science cart with a sink, an acid-resistant counter, an aluminum rod frame for attaching apparatus, an electrical plug and socket, and shelves with doors. We paid about $800. It saves time hauling – often delicate -items by hand, risking damage to desks, etc.

A modest-to-significant investment: a dissecting microscope, binocular – great for viewing samples of plants, insects, hangnails, you name it – $100 and up

Similarly: a compound microscope – for magnification to, say, 400x; get a light source with it, and a set of microscope slides (blank ones for your own samples – thin glass rectangles). You might also get a set or sets of prepared slides of biological samples – $200 and up

Light sources: more as a tool but having other uses, an LED light bar in a small handheld light

Tools – to make some lab devices as we did – lens holders, launching platforms, etc.

Screwdrivers (flat blade and Phillips; including some fine, small blades for tiny screws)

Pliers – regular and needle-nose



Bubble level

Hacksaw and a few spare blades

Electric drill; drill bits (a set of sizes); screwdriver bits; chuck key

Set of files

L- or T-square for measuring items to be cut

Heat gun – hotter than a hair dryer

Soldering iron, fine tip for electronics, broader for heavier work


Desoldering tape (woven copper)

Glue, electrician’s tape, duct tape

Teflon tape (a plumber’s supply) for sealing threads on pipes

Electrical extension cords

Power strips, with surge protection

Small electronic “balances” with ranges of 10g or 100g (or more) – $25-50 or more

Lots of fasteners – wood screws, nails, machine screws, nuts, sheet metal screws, washers, grommets, standoffs in various sizes

Spare pieces of wood

Heat gun – to shrink heat-shrink tubing, warm some equipment, set some adhesives

Marble slab for experiments with flames

Aluminum foil -e.g, as light shield for pots used in growing plants hydroponically

Pitchers and large bowls for experiments with water

Paper towels, for lots of cleanup (and for making flash paper)

Book matches


In general: don’t overlook the little things whose lack will suddenly stall a nice demo or experiment – e.g., tape, weighing paper, a stirrer


Gloves – latex or nitrile, youth and adult sizes

Thermally insulating gloves for dry ice, hot glassware, etc.!

Safety goggles, in youth and adult sizes

Lab coats, in various sizes

First-aid kit

Acid spill kit (bucket with commercial sorbent or sodium bicarbonate; squeegee and garbage bag)

Plastic 5-gal buckets for safely transporting strong acids in glass bottles

Mostly chemistry

Weighing paper for weighing out chemicals

Small spatulas for doling out chemicals (but do abide by the lab rule – no spatula goes into the reagent bottle, and no reagent ever gets put back into the reagent bottle with the risk of contamination)

Glass stirring bars – even make your own

Precision adjustable pipettors, 0.1 to 5 ml ($140 + supply of tips)

Big pipettor, fixed volume, and tips – 5 ml

Stirring hot plate ($120)

Teflon-coated magnetic stir bars to use with the stirring hot plate

Chemical glassware and associated items:

Beakers of sizes from 50 to 600 ml (rarely need the biggies)

Test tubes – you can get by with a common size such as 10 cm by 1 cm diameter, or add small ones for micro-assays

Test tube rack

1 or 2 50ml burettes with stopcock and grease for titrations

Graduated cylinders for making solutions– some inexpensive plastic, some glass, in sizes 10 ml to 250 ml

Volumetric flasks with ground-glass stoppers, for mixing up precise concentrations of solutions – 25 to 250 ml (ca. $10 on up)

Funnels – some simple plastic; at least one nice ceramic filtering funnel

Filter paper – fine/slow and fast, to fit the ceramic filtering funnel

Ceramic mortar and pestle, for grinding samples

Test-tube and burette cleaning brushes – long handles

Electrical heating tape to wrap around flasks

Tygon tubing in various sizes

pH meters – real ones, not passive ($80)

Clamps for glass flasks

A ring stand or two

Ring clamp to hold a round distillation vessel

Boiling chips (marble, ceramic shards, or small stones)

Metals and semimetals – Al, Fe, Ga, In, Sb, Sn, Cu, Bi, Zn, Pb, Si, Ni – supplier is!

Charcoal, as mainly carbon

Mg ribbon – fantastically bright light – warn students not to focus on it; keep their eyes moving!

Glucose meter ($40) – follow the reaction of starch breaking down into glucose

Graphite welding rods, as inert electrodes for electrolysis of water- any welding store

Atomizer bottles – empty bottles from eyeglass cleaner or nasal spray

Chemical reagents – always know the precautions and always read the materials safety datasheet (MSDS), which is available by Google search such as “Potassium nitrate MSDS”

Household items, useful for a number of demos and experiments

Sodium bicarbonate, NaHCO3 – a weak base, and a nice source of CO2

Vinegar, a solution of acetic acid, CH3COOH – a weak acid

Borax, for some odd experiments, Na2B4O7.10H2O

Chlorine bleach, a solution of sodium hypochlorite, NaOCl

Ammonium hydroxide, a solution of NH4OH, called “ammonia” colloquially

Vegetable oil

Sodium chloride, NaCl, table salt

Flour – even as a combustible

Sulfur, S

Hydrogen peroxide, H2O2, a 3% solution in water with stabilizer; 20% is available in hair salons

Ascorbic acid, vitamin C (get pills with no binder) – reductant

From a corporate source, such as

Strong base: potassium hydroxide (lye, KOH) or sodium hydroxide (caustic soda or lye NaOH)

Strong acid: sulfuric acid (H2SO4), as a solution, or concentrated (dangerous but useful)

Strong acid, safer: hydrochloric acid (HCl; moderately pure form as muriatic acid at a hardware store), as concentrated solution

Strong acid and oxidizer: nitric acid, concentrated, for making flash paper, e.g.

Potassium permanganate: strong oxidizer, strong color

Potassium nitrate: oxidizer, and plant nutrient source

Specialty: Potassium dichromate: strong oxidizer, in demo on spontaneous combustion

Dyes and acid-base or redox indicators:

Phenolphthalein, the classic

Methylene blue

Luminol, for chemiluminescence = make your own glow sticks

Ethanol – solvent; substrate in esterification experiment

Methanol – solvent in some spectrophotometric determinations

Acetone- solvent, and substrate in flameless combustion; nail polish remover; also in bulk in hardware stores


Metal salts, including for flame colors:

Potassium chloride, KCl

Specialty: Lithium chloride, LiCl

Specialty: Rubidium chloride, RbCl

Specialty: Cesium chloride, CsCl

pH buffers, standards, at pH 4, 7, an 10

See also those listed under biology: plant growth and biochemistry

We have other reagents but they’re more specialized

Significant investment: reverse-osmosis and deionizer system, for supply of very pure water

Handy: Glassware drying rack: you can make your own with big board and dowels

Mostly physics

Thermocouple thermometer, e.g., Omega ($90; really useful),

and thermocouple wire and connectors

Electronics supplies – see separate listing, below

Magnets, esp. rare-earth (strong magnets), and simple horseshoe magnets to show field lines

¾”-diameter copper tubing, about 16” long at a hardware store – for the dramatic slowly falling magnet demo!

Magnet wire, very thin lacquer insulation, fine gauge (e.g., 33), on a spool

Gyroscopes – toy ones work fine ($5)

Optics – Edmund Scientific has them, though it’s become expensive; there are other suppliers

Simple spectroscopes for viewing light sources – plastic

Several glass prisms

A selection of converging and diverging lens (make your own holders, as from wood)

Color filters, gelatin or plastic – Wratten or Rosco

Polarizing filters – get from a camera store such as B&H Photo Video

Liquid crystal samples – they show temperature patterns

Fresnel lens sheet

Black-light bulb (near ultraviolet; usually incandescent, but there are LEDs, too)

High-density welder’s glass, for viewing Sun

My LED color mixer, made from LEDs and some electronics

Radiometer (4 vanes in a sealed glass ampule; turns in sunlight)

Specialty: Heat-absorbing glass; show the separation of visible light from thermal infrared

Gray card, photographic, or make your own, as calibration for incident light flux density


Springs, a selection – extension and compression types

“Fish scale” to measure pulling forces

Pressure gauge, reading + and -, 1 bar (atmosphere) up and down

Newton’s cradle – ball bearings on microfilament lines, in a row ($30) – fascinating momentum demo

Geiger counter kits from $130; get a uranium ore sample to “drive” it – ca. $100 for one sufficiently active

Several butane torches

Red, violet, and green laser pointers – $15 a set! Very useful

On demand, on the day of the demo or experiment

Liquid nitrogen – a few $$ per liter, but you need a pricey Dewar flask ($300) to hold it

Dry ice – $2 per pound at a grocery store

🡪 Get a foam picnic chest to hold it

Plasma ball for great electrical discharge phenomena

Tuning fork

Basketball, from your play yard – to show elastic rebound and loss; used in a great demo of “small ball on top of big ball” that rockets the small ball very high

Large ball bearing – to show both kinetic center-of-mass energy and rotational energy down a ramp

Large metal rod – handy to show diffusion of heat; attach bottle caps with wax at various points and heat the rod in the center

Sewing needle to float on very clean water

Dish detergent to break the surface tension


You can buy kits that let students try 20 to 50 different circuits as demos or experiments.

You may get into you or your students making your own circuits. In that case, read on.

Electronic multimeter – indispensable; – $25-50; volts AC and DC, ohms, amperes over various ranges; some offer measurement of capacitance or inductance

Tools – see earlier, esp. soldering equipment, side-cutters, pliers


You’ll use wire to carry small signals all over, or to carry significant power. For signals among all the components noted below, use fine wire, say, 22 gauge. Use solid core, not stranded, if you want to stick wires into breadboard holes, especially.

Get several colors, which can help in tracing circuits

For devices with significant power output (heaters, lamps, etc.), use heavier 18-gauge wire, such as classic lamp cord, two insulated wires in one insulated cord.

To make electromagnets or radio-frequency coils, get fine magnet wire

More specialized but fun for long-term projects: wire-wrap wire and tools. The wire is fine, at 30 gauge, and it has thin but very sufficient insulation that’s easily stripped off with a special tool. You connect wire-wrap wire to pins of devices with a twist-tool, also special

Alligator clips – These are sooooo handy to make temporary connections! Two clips, one on each end of a piece of wire

Connectors – we have about 100 types. There are make-and-break connectors that you can undo at will (slim ones for fine wires, or hefty spade lugs, or audio plug style), permanent crimp-on connectors. There are connectors for multiple wires at a time (ConX-All, Molex) with various numbers of pins.

Naturally, there are special connector to special sources, with a prime example being a power plug and its companion, a power socket.

For use in temporary circuits on a breadboard (but we have used them in a permanent board) there are thin, stiff pins that you can solder onto a bare wire.

Heatshrink tubing – When you make bare soldered joints you’ll want to insulate them. You can wrap them with electrician’s tape, but it’s tidier to slip heat-shrink tubing over the wire leading to the solder joint (far away enough not to shrink prematurely). After the joint cools, push the tubing along to cover the joint. Use a match or a heat gun to shrink it snugly

Switches – toggle (have handles), DIP (push little embedded handles), and more; there are switches for single lines or double lines and for single on-position or two on-position (SPST, DPST, DPST, DPDT); there are momentary contact and latching switches. Figure out your needs and get a few. There are tiny switches that mount on a perfboard or a breadboard, and others that mount through holes in chassis. There are also in-line switches, typically with a rotating wheel for controlling lamps.

“Passive” components

1/8- or ¼-watt resistors, in profusion – from 0.3 ohms to 10 megohms – you can buy assortments; get a fair number of common values such as 10, 15, 22, 33, 47,56, 68, 82, 100, 150, 220, 330, 470, 560, 680, 820Ω, and in kilohms 1, 1.5, 2.2, 3.3, 4.7, 5.6, 6.8, 8.2, 10, 15, 22, 33, 47, 56, 68, 82, 100, 150, 220, 330, 470, 560, 680, 820, and in megohms 1, 3.3, 10

Potentiometers – these are variable resistors that you adjust with a dial (on a ¼” shaft, or tiny ones with fine-screwdriver slots) – common ones are 5 kΩ, 10 kΩ, 50 kΩ

Capacitors – there are many types: ceramic (small values), polyester (medium), electrolytic (big values; note that these are polarized and cannot be used with reverse voltage). Get an assortment, or read some schematics for circuits you want to build before buying

Inductors – these are less frequently used in simple projects

Active components – discrete components, as opposed to integrated circuits

Diodes – again, many types – basically low-signal and power diodes, as well as Schottky (no bias) and Zener (fixed breakdown voltage, to set reference voltages) – get a few 1N4148

You might get into AC power devices, using silicon controlled rectifiers, Triacs, etc.

Photodiodes for light detection

Transistors – also many types, especially junction vs. field effect, NPN vs. PNP, and small-signal vs. power. Get a few small-signal ones, such as 2N2222A (NPN type), and 2N2907 (PNP), and some MOSFET for larger currents (IRF Z34)

LEDs – light-emitting diodes – Get a few of red,, green, and blue, low power (20 or 40 milliampere current), but also think of fun with power LEDs, up to several watts; there are various packages and degrees of directionality of output; yet another is a thermocouple readout

Integrated circuits – So many types. You’ll get used to reading the datasheets at DIgiKey or online! They’ll guide you to just what you need

Operational amplifiers – really cool way to get any amplification, and more; many types; a good old 741 is useful, and an ICL7650 is low-noise, low-offset. Some of my favorite circuits with op amps: one gets a tiny current from a photodiode and creates a significant voltage, as a light sensor; another is an audio pre-amp; yet another is a controlled current source for an LED

555 timer – a workhorse

Voltage regulators – common ones are 3.3V, 5V

Precision voltage references – these are mostly references per se, not power outputs

Be sure to get DIP (dual inline pin) sockets for these, not surface-mount devices that are hellish to solder to; common ones have 6, 8, 14, or 16 pins

Breadboards for placing components and hooking them together. They have lines of holes at 0.1” spacing. You can insert wires or the pins of resistors or integrated circuits, etc. to make connections

Chassis – You may want to make some permanent pieces in aluminum boxes. If you do, be sure to consider buying hole punches to avoid endless filing

Power supplies – Lotsa options here. There are what are called wall chargers, akin to phone chargers but having simple coaxial connectors; you can cut the ends off to get two free wires onto which you can solder pin connectors and plug those pins into a breadboard

Battery holder, if you’re going this way – esp. for AA cells and for 9V batteries (clips)

Specialty items include optoisolators, logic gates (don’t go overboard; AND, NAND, NOR, XOR) and multiple gates (latches, multiplexers); thermocouple wire (get an Omega Engineering catalog – full of great info!)

Other neat items, low cost:

Analog-to-digital converters (ADCs) to allow a sensor such as a photodiode to feed into a digital computer

Accelerometers – 1- to 6-axis, to detect and record motion of many types

Digital displays – These can be nifty. You can buy small ones for $15 that just read a scaled analog voltage; be sure not to exceed their input voltage range, which is often just 200 mV; of course, there are ones that tiny monitors that display lines of characters

Inexpensive oscilloscope

Mostly biology – see general purpose items above re microscopes, slides

Dissecting microscopes ($180)

Microscopes ($100-300)

Microscope camera that fits down the tube – e.g., from Amscope ($95)

Dissecting scalpel and spare blades – caution! – also get a small “sharps disposal container for used blades

Terrarium, for both long-term plant growth and a controlled environment

Petri dishes for microbial growth

(Borrow from a kitchen) Pressure cooker- to sterilize Petri dishes and growth media

Agar, to make growth media

Starch, also

Parafilm, wide, thin “tapes” of wax for sealing Petri dishes

Plant growth items

There are many fine experiments, growing plants in soil

Pots, potting soil (even better, real soil)

Hydroponic growth:

Pots with covers that can be drilled for the plant to emerge

Modeling clay to hold plant in place

Aquarium pumps to aerate and stir the nutrient solutions

Equipment from the chemistry listing to mix solutions

Chemicals to mix up the nutrient solution: There are options, but here’s a set we’ve used; I give the chemical formulas, since some chemical names can be ambiguous to people:

KNO3 (potassium nitrate) – for both K and N

KH2PO4 (potassium phosphate dibasic) – for both K and P

K2SO4 (potassis=um sulfate) – for both K and S

MgSO4.7H2O (magnesium sulfate = Epsom salts) or Mg(NO3)2.6H2O (magnesium nitrate)

For both Mg and S

CaSO4 (calcium sulfate) – for both Ca and S

KCl (potassium chloride) or CaCl2 (calcium chloride) or NH4Cl (ammonium chloride – for Cl

FeEDTA – ferric ethylenediamine tetraacetic acid (ferric versenate) – for Fe; any plant store has it

ZnSO4 – for Zn alone (small quantity needed provides negligible S)

CuSO4.5H2O – for Cu alone

MnSO4.2H2O – for Mn alone

H3BO3 (boric acid) or Na2B4O7.10H2O (borax) – for B

Na2MoO4.2H2O (sodium molybdate) – for Mo; need so little – ask a chemist for a smidge

I have a spreadsheet to calculate the amounts of each.

The list of elements is then N, P, K, S, Ca, Mg, Cl, Fe, Zn, Cu, Mn, B, Mo; some plants need other elements in tiny amounts, such as V or Si

(A modest investment, $99, great for genetics): Wisconsin Fast Plants kit from Carolina Biological Supply

Grow lamps for plants – there are pricey ones but also inexpensive ones; make a frame with clamps to hold them

Some biochemistry


Sucrose (table sugar)

Pepsin HCl – a digesting enzyme

Papain, meat tenderizer – ditto

Potassium iodide (KI) and elemental iodine (I2), or buy the mix, KI3, for detecting starch; the two components are also useful in chemistry experiments

Antibiotics, including doxycycline and simple Neosporin paste

Color-blindness test chart

Optical illusion disks

Earth science – geology and meteorology (very incomplete list)

Mineral samples – see also chemistry: metal samples

Simple barometer for air pressure, to relate to weather

Wire loop for flame tests – use with butane torch: chemistry; same for borax to make borax beads

Rock hammer

Dissecting microscope – see under biology

Some neat specialty items



Steel plate, 24” square,

Raspberry Pi computers or Arduino computers – small, cheap, and with fantastic features for sensing and control that you won’t find handily anywhere else. Look these up on the Web, including their accessories such as USB hubs, breakout boards, and ribbon cables; great as dataloggers and controllers totally beyond any laptop – start at $25!

For the “RPi”:

Case, power supply (usually come with the kit)

Breakout board – to use on a breadboard to make connections to the input/output pins

40-pin or the like cable to attach to the breakout

Wireless dongle

HDMI cable to connect to a display (monitor)

HDMI to VGA adapter, in case you use an older monitor); some powered by the HDMI port work very well, and others don’t; some pass the audio signal, and some don’t – choose well

PiHub USB hub, sometimes needed for big projects

Note that RPis run on 3.3V signals and Arduinos run on 5V signals; each has advantages and precautions for not exceeding input voltages

High-speed camera, 240 frames per second (8x speed) or higher. This is great for recording and analyzing motion, such as we did in the “flight” of an eraser launched horizontally, to measure the vertical gravitational acceleration and show negligible horizontal acceleration. We have a classic Casio Exilim ZR-100 (up to 1000 fps!), alas, no longer made, but a GoPro ($300; up to 240 fps) is very good.

Parts to make a Chladni plate, a thin steel plate set into resonant vibration that patterns fine sand placed on it

Thin galvanized steel plate, 18” or 24” square; I think we used 18 gauge

“Vibration speaker(s)” – high impedance modules to mount on a surface; we used Tweakers, discontinued, but there are other makes available

Big-ticket items we acquired and love

Vacuum chamber system ($400)

Big bell jar (ca. 40 cm tall, 20 cm in diameter)

Vacuum pump

Vacuum / pressure gauge

Various fittings (see the page on demos)

Vacuum flask with 1-hole rubber stopper and glass tubing

Spectrophotometer – Sequoia Turner – measure absorption and transmission of solutions in 1-cm cuvettes over wide ranges of wavelengths, from 320 nm to 850 nm; a precision instrument, but pricey; ours is old but a comparable new one might be $1500 or more; great for many chemical assays and experiments

Spectroradiometer – ancient, but so useful for measuring the flux of radiation (UV, light, near infrared) at many different regions of the spectrum and many intensity levels

FLIR One Pro thermal imager for an Android phone ($370)

Specialized, cheap to expensive:

Distillation kit, including electrical heating tape

Round-bottom flasks with ground-glass joints

Distillation column


Tip, condenser to receiving flask

Temperature controller for water bath similar to one I made (equivalent store-bought ca. $250)

Autotransformer (can use big isolated transformer) ($600)

Model rockets with selection of engines of different specific impulse / delay / booster function

Sling psychrometer ($83) – measuring atmospheric humidity the classic way

Ferrofluid – magnetic nanoparticles in brake fluid – takes great shapes under strong magnets – be sure never to let magnets touch the fluid directly or you’ll never wipe it off; put the ferrofluid in a glass beaker

I can tell you suppliers for some things not readily available in your town – e.g., Carolina Biological Supply for Petri dishes on up to sulfuric acid

Maybe better way, as this list is soooo long: ask me for any set of demos and experiments what supplies and equipment are not clearly noted (and that may not be obvious) – for absolutely anything in electronics and electrical goodies – similar – not quite as quick as DigiKey

Jameco Electronics – for electronics kits and some components

B&H Photovideo – – for cameras of all types, optical filters, audio equipment – the gold standard for price, selection, and service!

Note: Highlighted items are links to demos or experiments that have been posted (or will be posted)