HISTOPATH LAB - Tissue Adhesive Preparation

Tissue Adhesives

substances that are used to secure tissue sections into the slides, preventing detachment during staining and processing

section retention, particularly for delicate and fragile tissues

what do adhesives improve

Not a necessary step for routine staining, provided that the slides are clean and free from grease

Is tissue adhesive a necessary step

methods that require exposure of sections to acid and alkaline, especially in ammoniacal silver solutions during staining

Tissue adhesives are essential for

drying

tissue adhesive is an alternative to

• Mayer’s egg albumin

• Dried albumin

• Gelatin 1%

• Gelatin formaldehyde mixture

• Poly-L-lysine

• APES

Common tissue adhesive

egg albumin, glycerin, & thymol crystals

Composition of Mayer’s Egg Albumin

dried albumin, sodium chloride, & thymol crystals

Composition of dried albumin

water, glycerol, & phenol crystals

composition of gelatin 1%

1%  gelatin & 2% formaldehyde

composition of gelatin formaldehyde mixture

Poly-L-Lysine

it is commonly used for IHC

3-aminopropyltriethoxysilane (APES)

Used for cytospin preparations and proteinaceous or bloody materials that need to be stained

Mayer’s Egg Albumin

provides reliable adhesion

dried albumin

a strong adhesive

gelatin 1%

a natural adhesive

Poly-L-Lysine

a synthetic adhesive

3-aminopropyltriethoxysilane (APES)

Chemically modified tissue adhesive

Adhesive mixtures are spread thinly on a clean, grease-free slide.

Principle of Tissue adhesion

A small drop is smeared over the slide (using a finger, sponge, or another slide) and excess is removed.

application of the principle

Promotes proper adhesion of tissue sections during processing.

purpose of tissue adhesion

Measuring cylinder	50 mL bottle	Funnel
Erlenmeyer flask	Thymol Crystals	Stirring rod
Filter paper	Glycerin	Egg white

Equipment and materials

Glycerin

Thymol Crystal

Egg Albumin

Syringe Used to measure the volume of glycerin and egg albumin

Dropper

Small beaker Mix egg albumin and glycerin

Glass slides Perform Pull Apart Technique

Modified equipment and materials

Egg White

specimen of choice

25 mL

volume of egg white and glycerol placed inside an erlenmeyer flask

coarse filter paper

what is used to filter the mixture

• some of the egg albumin that formed clumps

• artifacts that will obscure during microscopy

what does the filter paper filter out

prevent mold growth

purpose of thymol crystals

label

the 5th and 2nd to the last step of tissue adhesion steps

syringe

in the modified procedure, it is used to measure the volume of glycerin and egg albumin

PULL APART Technique

what technique is done after adding a Drop of Tissue Adhesive into the Slide

frosted area is on top

position of the slide during PULL APART Technique

smooth, single motion

pull apart motion

Mayer’s Egg Albumin

commonly used tissue adhesive

easy to make, is convenient, and it is inexpensive

why is Mayer’s Egg Albumin commonly used

oriented

what is done after adding a drop of adhesive on a clean slide for staining, mounting, and labeling

filter and add about 100mg crystals of thymol

composition of thymol

egg white

the source of albumin

acidic stain

the excess albumin takes up the

Humectant

composition of glycerin that prevents loss of moisture;

prevents drying and cracking of tissue section

aside from preventing the loss of moisture, what does Humectant prevent