film emulsion for in situs

[Tamara Western]

	I am trying to buy NTB-2 emulsion for doing in situs and have 
found a Canadian supplier in InterSciences where it is $417 for 4 oz (118 
ml).  Can anyone recommend another supplier or 
know if I could get a smaller quantity?  In addition, I was told 
by the representative I talked to that, diluted, the emulsion should be 
used within a day, maybe within a week if kept at 4C.  As well, I was 
told that opened and undiluted, it would only last for one month.   I 
was wondering whether this is the experience of others working with this 
emulsion, and if there were any hints out there on how to preserve the 
emulsion for a longer period of time.

	Thank you very much.

	Tamara Western
	western at unixg.ubc.ca
	Botany Dept, UBC
	6270 University Blvd.
	Vancouver BC V6T 1Z4