Apparatus and Method for Processing Biological Liquids

Abstract

A method and apparatus for controlling the processing of a liquid sample, e.g., a blood sample, based on a measurement related to the sample's ability to coat a surface against which the sample is brought into contact while being routinely transported. Preferably, the sample is advanced through a tube, and the amount of sample residue remaining within the tube is measured and correlated to coating process subsequently carried out on the sample, e.g., a process for producing blood-smears on a microscope slide. In a preferred embodiment, the amount of sample residue in a blood-transport tube is used to control the motion profile (i.e., acceleration and velocity) of a drop-spreading member used to spread a blood drop on a microscope slide in an automated slide-making instrument.

1 . A method for controlling the processing of a biological liquid sample on a substrate, said method comprising the steps of (a) advancing a volume of said biological liquid sample completely through a tubular member, said tubular member having a characteristic affinity for said biological liquid that is at least similar to the affinity of said substrate for said liquid sample; (b) detecting a characteristic of a liquid residue remaining within the tubular member after said volume of sample has been advanced completely through the tubular member; and (c) controlling the subsequent processing of said liquid sample on said substrate based on said characteristic of the detected biological liquid residue.  
   
   
       2 . The method as defined by  claim 1  wherein said tubular member and said substrate are made from the same material.  
   
   
       3 . The method as defined by  claim 1  wherein said detected characteristic of the biological liquid residue comprises its optical absorption to electromagnetic radiation of a particular wavelength.  
   
   
       4 . The method as defined by  claim 1  wherein said detecting step is effected by irradiating said tubular member with electromagnetic radiation of a wavelength substantially absorbed by said biological liquid sample, said tubular member being substantially transparent to said radiation, and detecting the respective levels of radiation absorbed by said tubular member with and without a biological liquid residue present therein.  
   
   
       5 . The method as defined by  claim 4  wherein said tubular member is positioned within a light-integrating sphere in which said radiation can be introduced and detected.  
   
   
       6 . The method as defined by  claim 4  wherein said tubular member is cleansed with a liquid that is substantially transparent to said radiation prior to said step of detecting said respective levels of radiation absorbed by said tubular member.  
   
   
       7 . A method for controlling the processing of a biological liquid sample on a substrate, said method comprising the steps of (a) withdrawing a volume of a biological liquid sample from a container; (b) advancing said withdrawn volume of sample through a conduit leading to said substrate for processing, said conduit having a portion that is optically transparent to radiation of a predetermined wavelength that is absorbed by said biological liquid sample, said transparent conduit portion having a characteristic affinity for said biological liquid that is at least similar to the affinity of said substrate for said liquid sample; (c) detecting a characteristic of a liquid residue remaining within said transparent portion of said conduit after said volume of sample has been advanced completely through said transparent conduit portion; and (d) controlling the subsequent processing of said biological liquid sample on said substrate based on the detected characteristic of said liquid residue.  
   
   
       8 . The method as defined by  claim 7  wherein said detected characteristic of the biological liquid residue comprises its optical absorption to said radiation of a predetermined wavelength.  
   
   
       9 . The method as defined by  claim 8  wherein said detecting step is effected by irradiating said transparent conduit portion with said radiation, and detecting the respective levels of radiation absorbed by said transparent conduit portion with and without a liquid residue present therein.  
   
   
       10 . The method as defined by  claim 9  wherein said transparent conduit portion is positioned within a light-integrating sphere in which said radiation can be introduced and detected.  
   
   
       11 . A method for controlling the processing of a biological liquid sample based on the surface-coating characteristics of said biological liquid sample, said method comprising the steps of (a) advancing a volume of biological liquid sample through a tubular member; (b) detecting a residue of the biological liquid sample remaining within the tubular member after such volume of sample has been advanced through the tubular member; and (c) controlling subsequent processing of said biological liquid sample based on the residue detected.  
   
   
       12 . The method as defined by  claim 11  wherein the amount of said residue is detected photo-electrically.  
   
   
       13 . The method as defined by  claim 12  wherein said detecting step is effected by irradiating said tubular member with electromagnetic radiation of a wavelength substantially absorbed by said biological liquid sample, said tubular member being substantially transparent to said radiation, and detecting the respective levels of radiation absorbed by said tubular member with and without a liquid residue present therein.  
   
   
       14 . The method as defined by  claim 13  wherein said tubular member is positioned within a light-integrating sphere in which said radiation can be introduced and detected.  
   
   
       15 . The method as defined by  claim 13  wherein said tubular member is cleansed with a liquid that is substantially transparent to said radiation prior to said step of detecting said respective levels of radiation absorbed by said tubular member.