| A | B |
|---|
| What are the aromatic hydrocarbons | benzene, toluene, xylene |
| What are the chlorinated hydrocarbons | Chloroform, carbon tetrachloride |
| What are the essential oils | cedarwood oil, clove oil, origanum oil, sandalwood oil, limonene |
| Which clearing agent belongs to the aliphatic hydrocarbons chemical family? | Limonenes (histoclear and americlear) |
| Which clearing agent causes toxic fumes when heated and therefore cannot be disposed of by incineration or burning? | Chloroform |
| Cedarwood oil | Clearing agent that may clear from 95% alcohol |
| Which clearing agent is best for tough tissue | Cedarwood oil |
| What two clearing agents are also carcinogens | chloroform and benzene |
| Which clearing agent causes considerable hardening of tissue | benzene |
| Which clearing agent causes the least hardening of tissue | petroleum ether |
| Which clearing agent is good for small biopsies | clove oil |
| Desirable traits of a mounting media | flow easily between tissue and coverslip, releases air bubbles, compatible with tissue and staining procedure |
| What is refractive index | the measurement which indicates the degree a ray of light will bend as it passes from one medium to another |
| What are the natural resins | canada balsam, damar, cedar oil |
| What are the semisynthetic resins | euparal, diphane, ester gums |
| What are the synthetic resins | terpene polymers, polystyrenes, synthetic polymers |
| What are the aqueous mountants | simple syrups, gum arabic, glycerol gelatin |
| Advantage of xylene | makes tissue transparent |
| Limonenes are | Less toxic |
| Disadvantage of xylene | Hardens tissue (other than brains) excessively |
| Clearing agent that must be incinerated to be destroyed | toluene |
| Effect of incomplete dehydration on tissue blocks | Tissue will shrink & become hard |
| 3 additives increase adhesiveness of paraffin | beeswax/tallow/lard |
| When heating paraffin at what temperature should the dispenser be set? | 2-4°C higher than the melting point of paraffin |
| Why should paraffin be filtered? | To remove dust/dirt to prevent damage to knife |
| At what temperature do tissue antigens denature (rendering the tissue unacceptable for immuno)? | 70°C and above |
| 4 main purposes of vacuum impregnation on the tissue processor | remove air bubbles/remove clearing agent rapidly/decrease impregnation time by 1/3/prevent hardening of tissue |
