We pick up 10 sections on any needle/core biopsy of suspected tumour/lymphoma. Usually if immunostains are ordered, the request comes the same day our routine slides go out, or possibly the next day. Cutting them "up front" seems the prudent way to go if there is any risk of the biopsy being cut away during subsequent sectioning for immunostains. How about 1 stained and 3-5 unstained at each level? This has saved us precious tissue many times, especially when multiple markers are requested. If more markers are requested than there are unstained sections, the pathologist will priorize his request and we then cut more slides, trying to conserve as much tissue as possible.
As for retaining these unstained slides, they're definitely worth keeping until after the dx. is made, after that it's up to you how long you want to retain them in your protocol. Antigenicity and storage capacity/cost are among issues to be considered.
As Greg mentioned, this is from a Canadian viewpoint.
Eric Gagnon MLT
Kingston General Hospital
Kingston, Ontario, Canada
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