A new and improved "quick-hot Gram-chromotrope" technique that differentially stains microsporidian spores in clinical samples, including paraffin-embedded tissue sections
Moura, H.; Schwartz, D.A.; Bornay-Llinares, F.; Sodré, F.C.; Wallace, S.; Visvesvara, G.S.
Archives of Pathology and Laboratory Medicine 121(8): 888-893
1997
ISSN/ISBN: 0003-9985 PMID: 9278620 Document Number: 475582
This report describes a new and improved "quick-hot Gram-chromotrope" staining technique that detects microsporidian spores in clinical specimens, such as stool, urine, saliva, nasopharyngeal fluid, and bronchoalveolar lavage samples, as well as in formalin-fixed and paraffin-embedded tissue sections. In this procedure, the samples are stained in heated (50 degrees C to 55 degrees C) solutions of crystal violet and iodine used in Gram's stain, followed by a modified chromotrope solution (heated to 50 degrees C to 55 degrees C). The modified stain is composed of chromotrope 2R (1%), fast green (0.15%), and phosphotungstic acid (0.25%). With this stain and the new protocol, microsporidian spores are stained dark violet against a pale green background, and the total staining time is shortened to 5 minutes. This new technique is fast, reliable, and simple. It can be easily adapted for use in clinical laboratories.