Flow cytometry-based systems and methods for detecting microbes

Abstract

In various embodiments, the present disclosure describes methods and systems for detecting microbes in a sample. The methods are generally applicable to quantifying the number of target bacteria in a sample counted from a detection region of a flow cytometer histogram. The detection methods can be employed in the presence of other microorganisms and other non-target microbe components to selectively quantify the amount of a target microbe. The methods are advantageous over those presently existing for testing of foodstuffs and diagnostic evaluation in their speed, accuracy and ease of use. Various swab collection devices and kits useful for practicing the present disclosure are also described herein.

1 . A method for standardizing the performance of a first flow cytometer against a second flow cytometer, said method comprising:
 a) setting a first initial voltage and a first initial gain of at least one detection channel on the first flow cytometer;   b) introducing a plurality of beads into the first flow cytometer; wherein the plurality of beads comprises at least first beads and second beads; and wherein the first beads and second beads have different sizes;   c) detecting the first beads and second beads using the at least one detection channel of the first flow cytometer to provide first raw data;   d) plotting the first raw data into first histograms showing locations of the first beads and the second beads;   e) adjusting the first initial voltage and the first initial gain;   f) repeating steps b)-e) until the locations of the first beads and second beads are substantially identical with specified locations in the first histograms;   g) setting a second initial voltage and a second initial gain of the at least one detection channel in the second flow cytometer;   h) introducing the plurality of beads into the second flow cytometer;   i) detecting the first beads and the second beads using the at least one detection channel of the second flow cytometer to provide second raw data;   j) plotting the second raw data into second histograms showing locations of the first beads and second beads;   k) adjusting the second initial voltage and the second initial gain; and   l) repeating steps h)-k) until the locations of the first beads and second beads become substantially identical with the specified locations in the first histograms.   
     
     
         2 . The method of  claim 1 , wherein the at least one detection channel is FSC. 
     
     
         3 . The method of  claim 1 , wherein the at least one detection channel is SSC. 
     
     
         4 . The method of  claim 1 , wherein the at least one detection channel is FL-1. 
     
     
         5 . The method of  claim 1 , wherein the at least one detection channel is FL-3. 
     
     
         6 . The method of  claim 1 , wherein the at least one detection channel is FL-4. 
     
     
         7 . The method of  claim 1 , wherein the first beads and the second beads are fluorescent. 
     
     
         9 . The method of  claim 1 , wherein the first beads and second beads are polystyrene, polypropylene or a combination thereof. 
     
     
         10 . The method of  claim 1 , wherein the first beads and the second beads are bacterial cells. 
     
     
         11 . The method of  claim 1 , wherein the first beads are epitope coated beads. 
     
     
         12 . The method of  claim 1 , wherein the second beads are epitope coated beads.