Doug Roberts droberts at
Fri Jun 4 10:13:09 EST 1993

In article <1993Jun2.180420.1 at> botjlh at writes:
>Does anyone know of a simple biochemical method for counting Cyanobacterial
>cells in culture?
>botjlh at

Back in my younger days working with Synechocystis at Purdue we would simply
take an O.D. reading and compare it to the standard growth curve. I don't 
recall the wavelength we used, somewhere around 560nm sounds right.

A more labor intensive way would be to plate out a serial dilution of your
liquid culture and count up the number of colonies on a plate with 50-250
colonies. This along with the dilution factor for that plate, gives the
concentration. (This assumes that your specific cyanob. will grow as a
colony,  I believe some of the filamentous types will not.) 

One more way would be to simply count the number of cells per unit area under
a microscope. There are special slides with grid marks of a certain size made
specifically for this purpose.       

Hope this helps, Doug       | - )  

droberts at

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