6/10/97

We are using some classical light microscopy staining techniques

to

screen our plant samples before we carry out EM on them. Many of

these

techniques include carrying the samples through xylene baths. We

have

been encouraged to find a safer alternative, if possible. I

remember that

years ago a xylene replacement was introduced into the

marketplace to

be used during paraffin embedding of samples, but I heard that

this was

not a good replacement, and it was discontinued. I don't know

what

happened after that or what is used these days.

Any help on this matter would be greatly appreciated. Thanks.

Paula.

Paula Allan-Wojtas

Food Microstructure Specialist

Agriculture and Agri-Food Canada

Atlantic Food and Horticulture Research Centre

Kentville, Nova Scotia Canada B4R 1A1

Tel:(902) 679-5566

Fax: (902) 679-2311

e-mail: allanwojtasp@em.agr.ca

I have come across the use of 'Histoclear' - sorry that's all I

know about

it. But in recent years we have used an even safer alternative

called

'Citroclear' (I believe its an extract of citrus fruits) - in the

UK this is

supplied by:

HD Supplies

44 Rabans Close

Rabans Lane Industrial Estate

Aylesbury

Bucks

HP19 3RS

UK

Phone Aylesbury (01296) 431920 - I will leave you to work out

the

international dialling codes

Fax Aylesbury (01296) 392121

The cost in our 1995 price list was:

catalogue number - CC500 Citroclear 5litres - 16.75 UK

pounds

25litres - 74 UK pounds

the prices are ex VAT(purchase tax) ex delivery and probably out

of date.

It appears to do much the same job as xylene but is ( at this

present time)

considered to be a lot less toxic. It's hazard data sheet lists

it's known

hazards as an irritant with the possibility of dermatitis after

long

exposure. Other characteristics are a strong fruity smell which

some people

like and some don't and a tendency to turn yellow and throw out

oily

deposits with prolonged storage in light. Oh the suppliers say it

is

bio-degradable as well and can be carefully disposed of down the

drains if

your regulations allow.

I don't know if you can source this in Canada but good luck in

your search.

By the way I have never used xylene outside of a fumehood in

years.

Malcolm Haswell

University of Sunderland

UK

Disclaimer - I have no connection with the company other than as

a satisfied

user.

es0mhs@environment.sunderland.ac.uk

was

here before me and I wasn't sure if it was available anymore or

where to

get it. It's interesting to read that it's not for use with

paramount- I

use it all the time, even use the Histoclear to thin the

paramount when

it starts to get too thick. I haven't noticed a big problem,

although it

takes the coverslip alot longer to dry down. In one of my

applications,

I rinse celloidin sections in Histoclear prior to pressing them

flat on a

slide and trimming the edges of the section with a razor blade.

I like

Histoclear better for this because is does take a while to

evaporate and

gives me more time to work with the sections before they dry out.

(They

need to stay moist throughout the mounting process.)

One more note. Althought Histoclear is supposed to be nontoxic,

it gives

me a headache, so I always work in a hood.

kna101@utdallas.edu

hybridization

work and use TBA (tertiary butal alcohol) to dewax some sections.

I

initially tried Histoclear, however this formed a coating over

the pieces of

tissue. Also, I have read that some use Hemo-D as a xylene

replacement. Hope this is helpful, Lu-Ann

LuAnn Bowman

BOWMANLA@em.agr.ca