Xylene Free Dewaxing

XYLENE FREE DEWAXING

Mel John del BarrioAotea Pathology

Dewaxing

A.k.a “ Deparaffinization

A key point in the histology staining protocols

Dewaxing agents be miscible with alcohol, wax and SAFE!!!

Xylene

A mixture of three aromatic hydrocarbons isomers related to benzene

102 synonyms Alkylation of crude oil,

Dehydrocyclodimerization 1st used in the 1950s as a safer

alternative Safety was questioned in the late 70s

What Xylene Does?

Melts latex gloves Melts the soles of your shoes!!! CNS depression Skin, eye irritant Nephrotoxic/Hepatoxic Teratogen/Fetotoxic Bone Marrow suppressant Carcinogen?

Information about the health effects of xylene led laboratory supplier to come up with a safer substitute that would still do the job of xylene.

Xylene substitutes is widely available.

Various journals published the use of other chemical for dewax

Dishwashing soap

Is a detergent used to assist in dishwashing

Cheap As!!!

Readily available

How does DWS clean your dishes

DWS contains a mixture of surfactants

Sodium Lauryl Sulfate

Surfactants lower surface tension of water

Surfactants molecules are composed of hydrophobic and water soluble component

Sodium Lauryl Sulfate

Dishwashing soap in Histology

Used for cleaning Laboratory Utensils, Benches etc

Used to remove LCS (Ventana) from IHC slides

Dewaxing of Slides for Staining

Dewaxing with Soap

1st published in Laboratory Investigation journal in 2001

Sweden and USA A popular topic in Histonet

H & E (Modified)

Place slides in oven for 5 to 10 minutes @ 60 C

Place slides in waterbath heated at 70C for 1 min and repeat

Wash slides in running hot tap water

Stain Slides

Appendix, Breast, Bowel, Liver and Skin were used

Slides were placed in Ordinary slides and Superfrost Plus

Modified H&E protocol done Slides were randomly labelled Slides were evaluated by 3 pathologists Slides were rated from 1=Very Poor to

5=Excellent

Appendix

Bowel

Breast

Liver

Skin

Findings

All slides (normal and soapy) were rated between 3 to 5

Soapy slides where less superior

Diagnosis is not affected

Difficulty of distinguishing

Specimen

KW RM JM Average

Appendix5 3 5 4.33

Appendix (S) 4 3 5 4.00

Bowel5 4 5 4.67

Bowel(S)4 3 4 3.67

Breast4 5 5 4.67

Breast (S) 5 3 5 4.33

Liver5 4 5 4.67

Liver(S)4 3 5 4.00

Skin5 5 5 5.00

Skin(S)4 4 4 4.00

Conclusion

Dewaxing with DWS is cheaper to use

The health hazards of DWS is lesser

H & E staining times will be shorter

THANK YOU!!!

Acknowledgements

Dr. Karen Wood Dr. John Maccaferty Dr. Rupa Maitra Kerry Patience Abed Kader Rene Buesa Leanne Ward Kim Brown Emily Workman

Reference Buesa RJ, Peshkov MV. Histology without xylene. Ann Diagn Pathol. 2009

Aug;13(4):246-56 Lars Falkeholm, Crawford A. Grant, Anders Magnusson, and Eva Möller.Xylene-Free

Method for Histological Preparation: AMulticentre Evaluation. LABORATORY INVESTIGATION. Vol. 81, No. 9, p. 1213, 2001

www.histonet.com http://www.osha.gov/SLTC/healthguidelines/xylene/recognition.html http://www.oehha.ca.gov/water/phg/pdf/xylen_c.pdf www.wikipedia.co.nz Ventana IHC staining manual http://chemistry.about.com/od/howthingswork/f/detergentfaq.htm www.chemistry.co.nz