Signedon sticker on knife holder: DU PONT [in ellipse] Instruments
on underside of case: Dennison / U.S.A.
Inscribedon knife holder: 35013075
on sticker on knife holder: Diamond Knife
on label on plastic box: Recommended microtome setting 40°. / Included angle 48°. / Ninety Day Warranty / See Product Bulletin / WARNING / CONTENTS EXTREMELY SHARP AND FRAGILE / A-70498 Printed in U.S.A.
on bottom of plastic box: Dennison / U.S.A. / DES. PAT. APPLIED FOR / PAD. PAT. 1,838,102
on the outside of storage box: Dr. Wolcott
on the side of the storage box: EM DUPONT / KNIFE
FunctionThe diamond knife is used as a sample preparation tool in Electron Microscopy. The edge of a diamond knife needs to be so perfect that it can slice specimens as thin as 0.05 microns without artifacts when viewed under magnification as high as 100,000x.
The knife is based on the work of Fernandes Moran, which involves cleaving a special type of diamond (Brazillian Boartz) and polishing the edge, resulting in an extremely sharp and hard surface that is used for cutting epoxy-embedded specimens. This type of knife is still in use in the early 2000s.
Historical AttributesDupont's diamond knife business was originally formed in the 1960s as an outgrowth of a program to develop single-point diamond lathe turning tools for the Atomic Energy Commission.
Provenancegift of Louis Herlands, Cambridge, MA, 2003.