Use of laser flare-cell photometry to count anterior chamber canine leukocytes and latex beads in vitro.
OBJECTIVE
To determine whether the cell measuring function of a laser flare-cell photometer is accurate and reproducible, using an in vitro model.


METHODS
Leukocytes from 8 clinically normal Beagles.


METHODS
Latex beads 11.9 and 6.4 microm in diameter were used to simulate canine WBC and RBC, respectively. Beads were diluted to known concentrations, placed in a model eye, and counted by use of the laser flare-cell photometer. A range of protein diluents from 0 to 2,000 mg/dl was used to suspend beads and simulate anterior uveitis, when cells and protein would be in the aqueous humor. A similar series of experiments were repeated, using leukocytes isolated from the blood of Beagles.


RESULTS
The laser flare-cell photometer can count 6.4-microm beads reproducibly and linearly up to a total of 510 cells/mm3, and 11.9-microm beads up to 1,300 cells/mm3 over a protein range of 0 to 2,000 mg/dl. The instrument can also count canine leukocytes reproducibly and linearly up to 1,300 cells/mms over that protein range.


CONCLUSIONS
Cell and bead sizes and concentrations and protein concentrations were chosen to mimic the range observed in dogs with uveitis. Because the laser flare-cell photometer accurately counted these cells in a range of protein concentrations in the model eye, it has the potential for use in noninvasive quantitative evaluation and monitoring of uveitis in dogs.
Krohne
S G
SG
Department of Clinical Sciences, School of Veterinary Medicine, Purdue University, West Lafayette, IN 47907-1240, USA.
Reagan
W J
WJ
Welch
P M
PM
D000818:Animals; D000867:Anterior Chamber / Q000737:chemistry / Q000166:cytology* / Q000473:pathology; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D066298:In Vitro Techniques; D007834:Lasers; D007958:Leukocyte Count / Q000379:methods / Q000662:veterinary*; D016014:Linear Models; D008863:Microspheres; D009504:Neutrophils / Q000166:cytology; D010783:Photometry / Q000379:methods / Q000662:veterinary; D015203:Reproducibility of Results; D012710:Serum Albumin, Bovine; D014606:Uveitis, Anterior / Q000473:pathology / Q000662:veterinary*
D012710:Serum Albumin, Bovine