Contact Us

Looking for a Product? Have any questions? Reach out to Us. We will get back to you within a day!

4280 Marie Court
Fremont, CA, 94536
United States


At USA Pen Company, we craft pens and pencils in a small utility workshop of a house in Elk River, Minnesota.  We use exotic wood and acrylic to hand make our pens. Our selection over the past few months has evolved into an assortment of contemporary designs... Come take a look at our collection and choose your favorite to either gift to your loved one, or keep all for yourself! 

All our pens and pencils are handmade in the United States of America (USA).

Welcome to the art of pen and pencil making at USA Pen Company. 

Would you rather have synthetic plastic or the feel of rich natural wood in your hand? We make our pens with carefully selected exotic wood from different parts of the world! 

Do visit our Gallery and Lookbook. If you like any pen currently not available in our "BUY NOW!" page, email us the details and we will specially handcraft and ship it to you within 14 days of your order. 

We look forward to serving your needs. Thanks!

Centrifuge Guide

Service AI support guide for centrifuge questions. Please feel free to email us at

Why do centrifuge tubes leak?

Service AI

Most leaks are due to improper handling or sealing. Always refer to the Rotors and Tubes manuals before attempting to use the rotor.

 1.     OptiSeal™ : Make sure the neck area is dry and tubes are correctly filled.

 2.     Quick-Seal™ : Fill to the base of the neck leaving a small (approx. ¼" diameter) air bubble and seal with the proper Beckman Coulter heat sealer and seal former. For best results, follow the Quick-Seal™ user's booklet directions.

 3.     Open top tubes: Thinwall tubes must be capped and filled for use in fixed angled rotors (torque the cap to 120 inch-pounds). In swinging bucket rotors the fill level is 2 - 3mm from the top. Thickwall tubes (without caps) in fixed angled rotors need to be filled between half to three-quarters full. In swinging bucket rotors fill to within 2 - 3mm from top.

4.     Bottles: Always ensure all sealing surfaces and O-rings are dry. Wet O-rings can act as a pathway for fluids, causing a leak. Be sure all O-rings are present, in good condition, and are dry.

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