For small cells such as E. Coli, proteins, serum and malignant tissues. All-glass Dounce tissue grinders designed for fine particle size reductions without damage to cell nuclei. Supplied with two interchangeable pestles for use in the same tube. Pestle "A" is ground and polished to a clearance of .001-.003 in. Pestle "B" to .0025-.0035 in. Mortar has large reservoir and pouring lip. Wheaton-33 low extractable borosilicate glass.