Re: sample/sheath ratio after sort

From: Dennis J. Young (djyoung@UCSD.Edu)
Date: Mon Apr 10 2000 - 13:48:21 EST


The general estimate would be how much sample is used per hour divided by
how much sheath is used.
Or assuming 1 microliter per second of sample is used and that each drop
has 3.53 times the cube of the diameter of the nozzle, so 10^6 drops equals
3.53 ml for a 100 micron nozzle. (NOT 0.523 ml)
If the pressure is only around 12 psi, then the frequency of drops could be
say roughly 2.8 10^4 drops per second)
For 35 seconds (10^6 over 2.8 X 10^4):
35 microliters sample per 3.53 ml sheath.
So the sample is around 1% of the sorted droplet.

"A jet vibrated at the optimum frequency for droplet generation
(lambda=4.5d) will produce droplets of volume 3.53d^3. If they were
spherical, their diameter would be 1.9 times that of the jet."
page 103, Flow Cytometry: Instrumentation and Data Analysis. Eds. Van
Dilla, MA, Dean PN, Laerum OD, Melamed MR. Academic Press, 1985.

>At 05:40 PM 4/5/00 -0500, you wrote:
>>
>>Hi cytometry fans,
>>
>>  I have a client that wants to know how much of the drop volume will be
>>taken up by the sample fluid (I need a general estimate).  We will be using
>>an ELITE sorter (12 PSI) with 100 micron sort sense tip to sort. To make my
>>life easier, has anyone calculated the sample/sheath ratio after sorting at
>>a specific sample input pressure?  I thought about running a concentrated
>>blue dye and sorting under conditions similar to the eventual client sort
>>and then measuring the OD in a spec original sample vs. sorted sample.  Has
>>anyone tried this and was it possible to see any absorbance in the diluted
>>sort sample?  Looking forward to your replies,
>>
>>Kristi Harkins

---
Dennis

Dennis J. Young
Mail:<<mailto:djyoung@ucsd.edu>>
WWW:<<http://cancer.ucsd.edu/SResources/flow.htm>>

Flow Cytometry Core Facility
University of California, San Diego
Internal Medicine Group, Bldg #4, Rm 126
9500 Gilman Drive La Jolla  CA	92093-0671
Telephone:(858) 822-0407



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