# How to calculate confluency? thx so much - (Jul/23/2010 )

Sorry to bother you all. I routinely culture HEK293 for transfection. And I need to evaluate cell confluency with microscope only, is there a convinent way to calculate cell confluency just by microscopic observation? Is there other way to calculate adhere cells' confluency for transfection?

Most confluency measurements you see are estimations of the area covered. If you do this routinely, you will get better at it, but it isn't particularly scientific.

One more scientific method is to take pictures of several random fields and use software (such as imageJ) to determine the edges of the cells and from this the area of the surface covered, then subtract this from the total area. For this you need to know the area of the image taken in the first place.

Otherwise you can estimate the confluency based on cell number - Roche Lab FAQs (free on the web) has tables of the area of cell culture vessels and the approximate cell numbers you should get out of them.

Thank you so much