公开(公告)号：US3627424A

公开(公告)日：1971-12-14

申请号：US3627424D

申请日：1968-10-30

Applicant: BAXTER LABORATORIES INC

Inventor： DORMAN HORTON E ,  SOODAK CHARLES ,  CULLIS HERBERT M ,  MILLER C DAVID ,  RODRIGUEZ RODOLFO RAMIRO ,  YOUNGQUIST ERIC W

IPC: C12M1/34 ,  G06M11/00 ,  H03K21/08 ,  G01N21/00 ,  G01B11/00

CPC classification number: G06M11/00 ,  C12M41/36 ,  H03K21/08

Abstract: An automated device for detecting measuring and counting growing microcolonies of bacteria by their light-scattering property. The growing bacteria are contained in glass capillary tubes filled with nutrient agar and are counted by passing the capillary tubes through a narrow beam of light. The tubes are mounted in a holder which is, in turn, detachably secured on a carriage. The carriage is translated in a direction lengthwise of the tubes and then sequentially moved transversely in a step equal to the distance between adjacent tubes. Transverse stepping takes place at the end of the longitudinal travel of each tube. A fixed light source and associated stationary optical means projects a narrow light beam which intersects the tubes as they translate. The presence of growing bacterial microcolonies causes light scattering which is detected in the form of pulses of light by a photomultiplier tube located opposite the path of translation of the tubes relative to the light source. The corresponding signal pulses produced by the photomultiplier tube are counted by an electronic counting circuit which provides a fast count of the particles scanned.