What Our Customers Say About Us...
...in Reviews on Google Places. Some are excerpts. Read the whole review by clicking on the names of the reviewers.
Deshana Barua: I brought some glass tubes to display my propagations and replace a broken one. Their prices are very reasonable (it’s impossible to buy just a single piece from online retailers like Amazon, which I’d rather not support anyway) and they processed my order and shipped very quickly. They arrived well-packaged with no broken glass and appear to be well-made.
Holly Christensen Ordered 15 test tubes. Very well packaged, quick delivery times, high quality test tubes that feel great. Thanks for the great service!
Anna Hovius I was pleased with the response that I got at Indigo Instruments - very helpful, very courteous and polite. I really appreciated the way you handled my very small purchase - like it was a... more
Lindsay McLennan Great service! I forgot to order the corks with my tubes and they had them shipped out that day and arrived at my door within 4 days! WOW! Great company to deal with. Happy to have found them before the Christmas Season arrives, as we are making these adorable Reindeer hot chocolate gifts. Thank you!
Lisa Harpster We love Indigo Instruments! They are super responsive, fair pricing, flexible and they are total problem solvers.
Some Blogs on Test Tubes & Corks
Borosilicate Glass Physical Properties
Borosilicate glass, sometimes referred to as "pyrex" is standard in lab glassware. It's resistant to thermal shock and is food safe because it is completely LEAD FREE compared to glass used in cut crystal, etc.!
See the tables below for physical characteristics. The first row lists the coefficient of linear thermal which is the best indicator for resistance to thermal shock . It is roughly1/3 of soda lime glass, the type most commonly used in food & drink.
| Borosilicate Glass Properties - Physical Data |
| Physical Performance |
Numerical Value |
Unit |
| Coefficient of mean linear expansion (20°C; 300°C) |
3.3 ± 0.1 |
10-6K-1 |
| Transformation Temperature |
525 ± 15 |
°C |
| Softening Point |
820 ± 10 |
°C |
| Working Point |
1260 ±20 |
°C |
| Density at 20°C |
2.23 ± 0.02 |
g/cm3 |
| Mean Thermal Conductivity (20°C-100°C) |
1.2 |
w/rn2k |
| Refractive Index |
0.92 |
1 |
No Glassware Returns
If you are unsure what glassware is best for your needs please contact us before ordering.
Glassware cannot be returned for any reason; this is for your safety and ours. It would be prohibitively expensive to test for bacteriological, chemical or radiological agents since there is no way to tell if glass has been contaminated just by looking at it. We would have to throw it away even if you claim to never have opened the package.
However, if the item is broken or clearly defective such as severely or chipped upon arrival, send us an image & we will refund you.
Safety Disclaimer-Warning
Handle glassware with care & personal protective equipment (PPE) - goggles & gloves because:
- Unless you poured it yourself, assume any liquid is hazardous.
- Hot & cold glass looks the same & does not have to be red to cause burns. Unless it was in the freezer, assume it is hot.
- Borosilicate glass will withstand a fair degree of thermal shock but unless your intent is to see if you can make it crack, don't toss recently heated glass into a cold water bath.
- When borosilicate glass breaks, it makes sharp edges like any other kind of glass. Dispose of pieces carefully.
- See blog: Glass Test Tubes with Cork-Chemistry Kitchenware which includes a video on how to safely stopper test tubes.
