We routinely use the following Hew-Shue (1991) has described a useful pH indicator for working neutral buffered formalin solutions. Bromocresol purple (CAS: 115-40-2) , when added to formalin solutions, serves as an indicator of pH as well as, from a safety aspect, labelling the solution as formalin making redundant the dangerous "smell" test. At an acidic pH (5.2) the indicator colour is yellow whereas at pH 6.8, the colour is purple.
A saturated solution of the dye (about 0.2g/100mls) is prepared and 2 to 4 drops are added to 10 litres of neutral buffered formalin. Hew-Shue N (1991) "Bromcresol Purple as a Colored Marker and pH Indicator for Ten Percent Neutral Buffered Forrnalin" J Histotechnol 14(4):257-260. Regards Tony Henwood JP, MSc, BAppSc, GradDipSysAnalys, CT(ASC), FFSc(RCPA) Principal Scientist, the Children's Hospital at Westmead Adjunct Fellow, School of Medicine, University of Western Sydney Tel: 612 9845 3306 Fax: 612 9845 3318 Pathology Department the children's hospital at westmead Cnr Hawkesbury Road and Hainsworth Street, Westmead Locked Bag 4001, Westmead NSW 2145, AUSTRALIA -----Original Message----- From: Baldwin, Kathy via Histonet [mailto:histonet@lists.utsouthwestern.edu] Sent: Thursday, 7 June 2018 4:09 AM To: 'histonet@lists.utsouthwestern.edu' Subject: [Histonet] pH of formalin Hi Histonetters Is anyone out there monitoring their Ph of the formalin they use? If do how often? Thanks S Kathy Baldwin ASCP, SCT Pathology and Cytology Manager Ph 812-996-0210 Fax 812-996-0232 CONFIDENTIALITY NOTICE: This e-mail message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information or otherwise protected by law. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet This message is intended for the addressee named and may contain confidential information. If you are not the intended recipient, please delete it and notify the sender. Views expressed in this message are those of the individual sender, and are not necessarily the views of NSW Health or any of its entities. _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
