A new and improved "quick-hot Gram-chromotrope" technique that differentially stains microsporidian spores in clinical samples, including paraffin-embedded tissue sections.
OBJECTIVE
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.


METHODS
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%).


RESULTS
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.


CONCLUSIONS
This new technique is fast, reliable, and simple. It can be easily adapted for use in clinical laboratories.
Moura
H
H
Division of Parasitic Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30341-3724, USA.
Schwartz
D A
DA
Bornay-Llinares
F
F
Sodré
F C
FC
Wallace
S
S
Visvesvara
G S
GS
D000818:Animals; D001826:Body Fluids / Q000469:parasitology; D018929:Cell Culture Techniques; D005243:Feces / Q000469:parasitology; D005840:Gentian Violet / Q000737:chemistry*; D006801:Humans; D007411:Intestinal Diseases, Parasitic / Q000175:diagnosis*; D016816:Microsporida / Q000737:chemistry / Q000302:isolation & purification* / Q000502:physiology; D016881:Microsporidiosis / Q000175:diagnosis*; D016612:Paraffin Embedding; D010619:Phenazines / Q000737:chemistry*; D013170:Spores / Q000737:chemistry; D013194:Staining and Labeling / Q000379:methods*
C035863:Gram's stain; D010619:Phenazines; D005840:Gentian Violet