Evaluation of Leishmania antigens preparation and storage for use in enzyme immunoassays.
The influence of time and temperature on the storage of an alkaline antigen of L. major-like and L.(V.) braziliensis promastigotes added or not of a proteases inhibitor (PMSF) was evaluated by means of an IgG-ELISA. Antibodies in assays using L. major-like antigen stored at -20 degrees C for 6 months had a statistically lower geometric mean titer (GMT) and different 95% confidence interval limits (CL) than antigens stored otherwise, as assessed by the "t" statistic. The PMSFL. major-like antigen after storage for 6 months at a temperature of 4 degrees C had the same GMT and 95% CL displayed at time zero as well as when storage for 4 and 6 months at -20 degrees C. Significant differences were not found when L.(V.) braziliensis antigens were stored at times and temperatures mentioned; the PMSF antigen stored for 2 months at -70 degrees C resulted in a lower serum GMT and 95% CL than any other, as assessed by the "t" statistic. Antigen performance did not show any statistical difference associated to the addition of PMSF within the same species; the largest difference between antigens was that between PMSF-L. (V.) braziliensis and L. major-like without PMSF.
Celeste
B J
BJ
Departamento de Medicina Preventiva, Faculdade de Medicina, Universidade de São Paulo, Brasil.
Guimarães
M C
MC
de Souza
J M
JM
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000953:Antigens, Protozoan / Q000302:isolation & purification*; D002648:Child; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques / Q000706:statistics & numerical data; D007892:Leishmania braziliensis / Q000276:immunology*; D018320:Leishmania major / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011309:Preservation, Biological; D013696:Temperature; D013997:Time Factors
D000953:Antigens, Protozoan