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DDK offers a wide variety of ultramicrotomy products and services

Maximizing the physical properties of diamond through exceptional craftsmanship, sophisticated equipment and customized engineering, DDK's longer-lasting, diverse line of knives feature precise edges and an unconditional guarantee.

Unique Knife Properties | Choosing the Proper Angle | Knife Care and Use | Knife Selection | Store

electron micsoscopy knivesULTRATHIN DIAMOND KNIVES

The edges of our diamond knives have been shown to have a radii of curvature of 20 Angstroms or less, the sharpest edge that has ever been put on any material. Flaws in the facets that form this edge give unacceptable results, so great effort is made to achieve facets that are smooth on an atomic scale.

Angles Edge Length Thickness
Routine Sectioning 45° from 1.0-6.0mm 30-200nm
EELS (special request) 45° from 2.0 - 4.0mm 10-30nm
Soft biological 35° 1.0-6.0mm 30-200nm
Hard material samples 55° 1.0-6.0mm 30-200nm


DDK manufacturers high quality diamond histo knives for preparing thick sections. The DDK histo knife is made from natural diamond and manufactured using the same processes as the ultrathin knife. We provide customized testing, free knife evaluations, and we creatively design cost effective solutions to meet your budgetary requirements!



DDK stocks boat styles to fit all modern & older style ultramicrotomes and cryo accessories. DDK boats are typically black but can be made a color of your choice. All DDK boats use materials immune to common solvents and cryo temperatures.

You'll need to specify boat style and blade angle when ordering a diamond knife. Click the following link for our blade angle guide.



DDK will restore your cutting edge to its original condition to extend the life of your knife. Your resharpened knife will have the same cutting edge length and be backed by the same unconditional guarantee as your original new knife. We will accept knives from any manufacturer and in any condition as an "exchange" knife, enabling you to get a new DDK knife for the resharpening price.Our diamond knives can be resharpened an unlimited number of times because when your diamond is worn, we replace it with a new one at the resharpening price. Ask us about our coupon promotions to provide you with more value for your dollar.


Now that you have selected the application, boat style and included angle, you can proceed with confidence toward buying your diamond knife. If you are still uncertain because of unique samples or demands, DDK has developed a no-risk sample evaluation program.

Send us a bit of the sample you would like to have sectioned. We will, with your guidance, determine how best to prepare and section the material. After checking our work in our TEMs here, we will forward to you grids of sections for your evaluation. In this way we can help you overcome any initial fears regarding the application of ultramicrotomy and durability of the expensive diamond knife.

This free custom testing program benefits us both. DDK's technicians get the opportunity to add to the wide variety of materials they have successfully sectioned. You are able to prove that the technique will contribute to your work, minimizing the risk of the equipment investment. This process helps us promote what we think is the fastest, most effective way of preparing a sample for TEM ... ultramicrotomy with a diamond knife.


Our quality control technicians are cutting ultrathin sections all-day, every-day and have 25 combined years of experience. In addition to being proficient at all the technology surrounding operating a TEM lab, their expertise at the craft of ultramicrotomy is truly unparalleled. They have experienced first hand the widest variety of cutting problems (and successes) possible.

You can take advantage of this expertise if you are just starting in ultramicrotomy or need a quick refresher course. A new technician or experienced staff member who is all thumbs at the microtome may benefit from an independent evaluation of their problem and an alternative approach to its solution. Our free ultramicrotomy training can be the answer to your needs.

You'll learn about:
  • Trimming blocks
  • Operating a microtome
  • Approaching the block face
  • Taking survey sections
  • Cutting and collecting ultrathin sections
  • Evaluating and troubleshooting the end product

Although beginning training will be done with our standard embedments, bring your own for more meaningful assistance. You'll take home grid boxes of sections you've cut yourself. DDK is conveniently located 30 minutes south of the Philadelphia International Airport and 5 minutes from Wilmington's Amtrak station or Interstate 95. Training can usually be accomplished within one day. You can contact us now to get answers to your questions, receive references and make reservations.