Rare cell population (1%) and sample collection

[Nina7]

Hi there!

I have a 2-fold question. First, I am interested in a rare cell population (around 1% of total lymphocytes), and would like to know the least amount of events I need to collect.

I have been collecting sound 10,00o whenever possible, but was wondering if it would be OK to go down to 5,000. (Only phenotypic analysis)

Another question, I am using a LSRII. What is the max number of events I can collect per second?

Thanks a ton!

Nina7

[bigdmajor]

How many events you record is completely up to you, but in general, the rarer the population is, then the MORE you should collect. If you only record 5000 events, then your 1% population would yield 50 cells.... which is not impressive on a dot plot or histogram. Why not spend the extra few minutes and record until the entire sample is done?

The LSRII is a higher end cytometer, so it can resolve populations a little better at higher rates, but the answer to this question is always the same on any cytometer:

Choose a flow rate that does not result in a loss of resolution; a slower flow rate is generally better.

The slower the flow rate is, then the more "single file" the cells are when they go throught he flow cell, which means more accuracy.

For our LSRII, one can go up to about 2000 events/second before significent resolution is lost, BUT OUR CYTOMETER IS NOT YOURS. Your's is likely to have different configurations and a different setup.

[Nina7]

Thanks for the reply!

I actually meant collecting 5000 events gated on the rare cell population, what would mean at least 500,000 total lymphocytes events collected (now I try to collect 10000).

Yes, it's always a challenge to now the exactly limitations of one cytometer...

Thanks again!

Happy Holidays!