Dehydration

DEHYDRATION

Jenivie Morillo Jose University of Santo Tomas National Children’s Hospital

 process of removing EXTRACELLULAR and

INTRACELLULAR water from tissue

IDEAL CHARACTERISTICS:  dehydrate tissue rapidly without SHRINKAGE

 not EVAPORATE very fast  able to DEHYDRATE even FATTY tissues  not HARDEN the tissue excessively  not be TOXIC to the handler

THREE COMMONLY SOLUTIONS: alcohol, acetone, dioxane ALCOHOL METHOD -use of ETHYL ALCOHOL, METHYL ALCOHOL, BUTYL and ISOPROPYL ALCOHOL are recommended for routine dehydration of tissues -BUTYL and ISOPROPYL ALCOHOL is SLOW DEHYDRATING AGENT -consists of passing the tissue through a series of progressively more concentrated alcohol baths -the more DELICATE the tissue, the LOWER is the grade of alcohol and SMALLER the intervals should be between the strengths of the ascending alcohols

ACETONE METHOD  -for MOST urgent biopsies  -UNSUITABLE for routine work

DIOXANE METHOD (Diethylene Dioxide)  -UNIQUE reagent(miscible with both water and

molten paraffin wax)  -should be used only in A WELL VENTILATED LABORATORY  -EXCELLENT DEHYDRATING and CLEARING AGENT

TETRAHYDROFURAN  -used as BOTH DEHYDRATING and CLEARING  

 

AGENT (miscible in both water and paraffin) -dissolve FATS -miscible in LOWER ALCOHOLS, ETHER, CHLOROFORM, ACETONE, BENZENE and XYLENE -doesn’t dissolve out ANILINE DYES -MOST STAINING procedure gives improved results

CELLOSOLVE(Ethylene Glycol Monoethyether)  -with RAPID ACTION without OVERHARDENING

and DISTORTION of TISSUES

Tri-ethyl Phosphate  -removes water very rapidly  -produces very little DISTORTION  -soluble in ALCOHOL, ETHER, BENZENE,

CHOLOFORM, ACETONE and XYLENE  -produces MINIMUM tissue shrinkage

Thank you 