Operating Instructions for the BioPulverizer
The BioPulverizer is an impact tool that can reduce tissue hard frozen to liquid nitrogen or dry ice temperatures to a coarse frozen powder. The method is especially useful for tough tissue such as skin, cartilage, and cornea. Cryo-fracturing with the BioPulverizer is often an initial step for cell disruption. Final disruption of the cells is accomplished using mechanical disrupters and/or aggressive extraction solutions (see homogenizer review at https://biospec.com/resources/cell-disrupters-a-review).
1) The mortar consists of two parts... an inner s.s. sleeve and an outer s.s. cup. The inner sleeve of the mortar nests inside the outer cup. The hole in the inner sleeve receives the tissue sample. Place the mortar and pestle of the BioPulverizer (BP) in an insulated container such as a styrofoam cup and thoroughly chill it with liquid nitrogen** or crushed dry ice. Stainless steel is relatively slow to cool down and, on the plus side, relatively slow to warm up. Slowly add liquid N2 to the stainless steel parts until the liquid N2 no longer flashes off as vapor and some liquid N2 lingers on the stainless steel.
2) Add pre-frozen (-80 deg C or lower) tissue to the well of the mortar. Fresh tissue will stick to an ultracold BP and the impact pestle cannot be inserted into the mortar well.
3) Remove the BP containing the tissue sample from the insulated container and place it on a sturdy lab bench. There will be ample time to utilize the chilled BP. Insert the pre-chilled pestle into the well of the mortar, patterned end down, and deliver two or three sharp blows to the pestle using the provided dead-blow hammer. Rotate the pestle slightly between blows.
4) Remove the pestle and the inner sleeve of the motar, thus providing easy access to the powdered sample.
IMPORTANT! Powdered tissue has a “dry” appearance and, with the exception of highly fatty tissue, can be poured into a test tube or plastic weigh boat containing extraction solution. Pulverized tissue thaws quickly when exposed to room temperature and humidity, so work quickly or you will have a sticky mess.
A small amount of liquid nitrogen can often be sourced from a local business specializing in welding equipment. Liquid nitrogen will store for hours in an insulated picnic jug or "Thermos" bottle. Wear safety glasses when pouring it.