Abstract: Photometric apparatus, for counting the particulate components in blood and for determining the degree of particulate agglutination, which comprises a cuvette for holding a blood bearing solution and an absorbent well for holding the cuvette. The well has a passage to allow communication between the cuvette and a detector which is capable of detecting the response of the particulate material to stimulating radiation. The absorbtive well has the characteristic of absorbing radiation at the wavelength which characterizes the response of the particulate material to stimulating radiation. The well advantageously prevents the detector from detecting radiation that would otherwise be reflected by the well whereby the linearity of the response of the apparatus is greatly increased. Linearity is further enhanced by assuring full crenation of the cells with a specific reagent.

Abstract: Photometric apparatus, for counting the particulate components in blood and for determining the degree of particulate agglutination, which comprises a cuvette for holding a blood bearing solution and an absorbent well for holding the cuvette. The well has a passage to allow communication between the cuvette and a detector which is capable of detecting the response of the particulate material to stimulating radiation. The absorbtive well has the characteristic of absorbing radiation at the wavelength which characterizes the response of the particulate material to stimulating radiation. The well advantageously prevents the detector from detecting radiation that would otherwise be reflected by the well whereby the linearity of the response of the apparatus is greatly increased. Linearity is further enhanced by assuring full crenation of the cells with a specific reagent.