| A | B |
|---|
| What are some reasons youd use an infiltrating media other than paraffin? | Tissue needs greater support, tissue may be adversely affected by heat, clearing agents and dehydrants are harmful to tissue |
| What solutions are used to "defat' | acetone and trichloroethylene |
| To ensure an even consistency with methyl methacrylates, the impregnantion process uses a mixture of? | monomer and benzyl peroxide |
| which emedding media is used to infiltrate tissue directly from aqueous fixatives? | carbowax |
| What are the advantages of using carbowax as an embedding medium? | water soluble at room temp, tissues arent dubjected to harmful processing reagents,adhesive properties are superior to paraffins |
| What is ester wax made of? | several stearates and a soft greasy material |
| what are the advantages of using ester wax over paraffin? | has definite finely crystalline structure, can get thin 1 micron sections, good support to fibrous tissue |
| What are the disadvantages of Ester wax | unable to preserve lipids, requires longer infiltration time than paraffin |
| Uses of methacrylates | phase microscopy, bone disease studies for undecalcified sections, renal biopsies |
| define polymerization | chemical reaction of 2 or more small molecules to combine to form a large molecule |
| define monomer | chemical compound tat can undergo polymerization |
| Depending on the chemical structure, methacrylates may be? | water soluble or non water soluble |
| How can the hardness of glycol methacrylates be modified? | varying the amount of co-monomer or water |
| When using glycol methacrylates the degree of polymerization is a function of? | time, temperature, concentration of catalyst |
| characteristics of epoxy resins? | forms links in all directions, reisistant to electron bombardment, ideal for EM, require cross linking agents, need transistional fluid |
| What is the most commonly used transistional fluid? | propylene oxide |
| which resin is not recommended for rapid processing of rush biopsies? | Araldite |
| Hardeners in epon? | DDSA and MNA |
| accelerator in epon | DMP30 |
| why does celloidin require dehydration | because it is not miscible with water |
| What water soluble resin is recommended for lipid studies? | Urea formaldehyde resin |
| Gelatin gives good support for? | Soft and pourous tissue |
| For hard or fibrous tissue and less time consuming, what embedding technique should you use | agar and ester wax |
