Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N1/00—Sampling; Preparing specimens for investigation
  • G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
  • G01N1/30—Staining; Impregnating ; Fixation; Dehydration; Multistep processes for preparing samples of tissue, cell or nucleic acid material and the like for analysis
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N1/00—Sampling; Preparing specimens for investigation
  • G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
  • G01N1/30—Staining; Impregnating ; Fixation; Dehydration; Multistep processes for preparing samples of tissue, cell or nucleic acid material and the like for analysis
  • G01N2001/305—Fixative compositions

Definitions

• the invention refers to a method of impregnating a tissue specimen with paraffin.
• tissue specimens are trea with a dehydrating agent, alcohol and acetone, respective before the tissue specimens are immersed in a bath of liquid paraffin.
• the pressure of the bath is lowered so muc that the respective dehydrating agent is vaporized and thereby evaporates from the tissue specimens as well-as from the paraffin bath, the pressure of the bath then being increased again to atmospheric pressure.
• An object of the invention is to provide a method of impregnation that eliminates the disadvantages of the methods known hitherto.
• Another object of the invention is to provide a method of impregnation in which the treatment with a dehydrating agent can be eliminated.
• the tissue specimen is immersed, either directly after an optional treatment of the tissue specimen with a fixing agent or after the tissue specimen optionally has been treated with a fixing agent and/or a dehydrating agent, in a bath of liquid paraffin which is kept below a predetermined temperature at which thermolabile component and properties of the tissue specimen undergo changes, and that thereafter, the pressure of the bath is lowered from atmospheric pressure to a predetermined pressure, at which water and/or, when appropriate, the dehydrating agent vaporizes. Then the pressure of the bath is increased again to atmospheric pressure.
• a tissue specimen When carrying out a histochemical diagnosis, normally a tissue specimen is first treated with a fixing agent, usually formalin, and thereafter with a dehydrating agent, e.g. methanol, ethanol or acetone, before the tissue specimen is immersed in a bath of liquid paraffin. In this bath the tissue specimen is impregnated with paraffin. The tissue specimen impregnated in this way with paraffin is then embedded in a paraffin block which can be cut by means of a microtome knife to obtain thin cuts (1-5 urn thic which can thereafter be examined in a microscope after the paraffin has been removed and after dyeing.
• a fixing agent usually formalin
• a dehydrating agent e.g. methanol, ethanol or acetone
• the tissue specimen is directly immersed into the paraffin bath.
• a paraffin having a melting point of about 37-44 C has been chosen and the bath is kept at a temperature of about 47 C at the most, i.e. below the temperature at which it has been observed that thermolabile components and properties of the tissue specimen begin to change. It should be pointed out that this temperature can vary somewhat depending on which type of tissue specimen one wants to examine.
• the pressure of the paraffin bath is thereafter lowered from atmospheric pressure to at least about 76 mm Hg, i.e. the pressure at which water boils at a temperature of about 46 C.
• the pressure of the bath is increased again to atomospheric pressure.
• the lowering of the pressure as well as the pressure increase must not take place too abrupt.
• the tissue material and cells present therein can burst through sudden pressure changes during the pressure lowering phase and can be compressed during the pressure increasing phase.
• the tissue specimen can also be treated with a dehydrating agent, for example methanol, ethanol or acetone, before the sample is immersed into the paraffin bath which also in this case is kept below the temperature at which thermolabile components and properties of the tissue specimen are changed.
• a dehydrating agent for example methanol, ethanol or acetone
• the pressure of the paraffin bath has to be lowered to at least about 510 mm Hg, i.e» the pressure at which acetone vaporizes at a temperature of about 45 C.
• the acetone will vaporize and evaporate from the tissue specimen as well as from the paraffin bath.
• the pressure of the bath must also in this case be lowered to at least 76 mm Hg.

Applications Claiming Priority (2)

Publications (1)

Family

ID=20359937

Family Applications (1)

Country Status (3)

Cited By (8)

Citations (1)

• 1985
  • 1985-04-23 SE SE8501959A patent/SE8501959L/sv not_active Application Discontinuation
• 1986
  • 1986-04-22 EP EP19860902936 patent/EP0220269A1/en not_active Withdrawn
  • 1986-04-22 WO PCT/SE1986/000185 patent/WO1986006479A1/en unknown

Patent Citations (1)

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