Biomedical Engineering Reference
In-Depth Information
TABLE 9.1
Test Solution
s
Solution
Additive
pH Value
A
2 L Water only
7
B
20 g Trypsin powder in 2 L water
7.8
C
40 g Surf powder in 2 L water
11
D
40 g Biozet powder in 2 L water
10.5
Biozet laundry powder contains two types of enzymes for biologically
active cleaning, anionic and nonionic surfactant for lifting dirt from clothes,
sodium perborate mononhydrate for oxygen bleach, sodium alumino silicate
for softening water, sodium carbonate for breaking up fatty soils, fluorescers
for brightening fabric, soil-suspending agent, and perfume (KAO, Australia).
The pH value of Solution D is 10.5.
In their experiment Yin et al. [5] used 16 lamb femurs from 6-month old
lambs purchased from a local market, which were stored in a refrigerator
at -20°C before all the joints were cut off using a diamond saw machine.
Four femurs were macerated in each solution and then stored in a closed
plastic container for 5 days at room temperature in a fume cupboard. After
5 days, manual removal of soft tissues was conducted using a rod, a cooking
knife, and a brush. Care was taken to avoid scraping, scratching, or cutting
bone surfaces. For safety reasons, all the manual removal was conducted
in the fume cupboard. When evaluating maceration of bones for soft tissue
cleaning, several aspects must be considered, including odor, soft-tissue
texture, ease of flesh removal, and bone quality [6].
The cleaned bone samples were stored in an isotonic phosphate buffered
saline (PBS) solution, with sodium azide as preservative, at room tempera-
ture. This solution, containing the identical mineral content to mammalian
cells, was prepared by dissolving 800 g NaCl, 20 g KCl, 144 g Na
2
HPO
4
,
24 g KH
2
PO
4
, and 0.2% NaN
3
in 8 L of distilled water, and topping up to 10 L.
The pH of the solution was about 6.8.
9.2.2 Preparation of Thin Sections
Yin et al. processed each femur macerated in each solution for thin section
preparation for microstructural analysis by scanning electron microscopy
following a standard protocol for thin section preparation.
Using a diamond saw, they then cut a suitably sized slab from the center
part of each femur macerated in each solution for mounting on a slide. The
slab was labeled on one side and the other side was lapped flat and smoothed
first on a cast iron lap with 400 grit carborundum, then finished on a glass
plate with 600 grit carborondum. After the slab had been dried on a hot plate,
a glass slide was glued to the lapped face of the slab with epoxy. Using a
thin section saw, the slab was cut off close to the slide. The thickness was
