I have Expi293 cell cultures (suspension). After counting them, the density turned out to be 4.26 x 10^6. I need to split them. Starting from this concentration, how can I obtain a 30ml cellular suspention at a density of 0.25 x 10^6? How many mL of cellular suspension (the one at a density of 4.26 x 10^6) and how many mL of medium do I need? I still have difficulties in understanding which kind of mathematical calculation do I need to use. Could you explain it to me?
Hello Rosario Rox
Use the formula C1V1= C2V2
C1= 4.26 x 10^6
V1= volume to be taken (Xml)
C2= 0.25 x 10^6
V2= required volume (30ml)
4.26 x 10^6 x Xml = 0.25 x 10^6 x 30ml
X= 0.25 x 10^6 x 30ml / 4.26 x 10^6
Therefore X= 1.76ml
So, add 1.76ml of cell suspension (the one at a density of 4.26 x 10^6) into 28.24ml of culture media to obtain 0.25 x 10^6 cell density in 30 ml cellular suspension.
Best.
Malcom's answer is perfect.
Here is another method: Want/have
Make sure you include the units so that when you cancel out the labels, the right unit is left behind. Called the Factor Label method.
1. Determine the total cells you want in the new culture.
0.25e6 cells/ml x 30ml = 7.5e6 cells
2. Divide that by what you have (the density) in the original (4.26e6 cells/ml)
7.5e6 cells /4.26e6 cells/ml = 1.76 ml.
3. Volume of media to add to get the right density in the new culture:
30ml (new total volume) - 1.76ml (cell volume adding) = 28.24 ml fresh media
Watching the units:
First calculation: "ml" cancels out = leaving "cells".
2nd calculation: "e6" and "cells" cancel out = leaving "ml".
Very old school but it works...
Kindly,
Kathy
Исходная концентрация клеток 4,26 Х 106 = 4 260 000 кл/мл
Необходимо получить 0,25 Х 106 = 250 000 кл/мл
4 260 000 кл/мл : 250 000 кл/мл = 17,04 кратно развести питательной средой
30 мл : 17,04 кратность = 1,76 мл
30 мл – 1,76 мл = 28,24 мл
Ответ: к 28,24 мл питательной среды нужно добавить 1,76 мл суспензии клеток с концентрацией 4,26 Х 106 кл/мл.
Поверка: (1,76 мл х 4,26 Х 106 кл/мл) : 30 мл = 249 920 кл/мл = 0,25 х 106 кл/мл
I always explain it the same way as Katherine. I think it is the easiest to understand.
I fully agree with the answer given by Lespek, it is the easiest way to get the solution.
I use Katherine's method if I'm seeding a specific number of wells etc. You can also slightly modify the way Katherine explained if you're going simply from concentration to concentration:
(concentration you want/concentration you have) X volume you want
(0.25e6 cells/ml / 4.26e6 cells/ml) X 30ml = 1.76ml of the counted suspension in 30-1.76ml media
Very simple. If you have 4.2×10^6 cells/ml or 4.2×10^6 cells/1000ul then for 0.25×10^6 cells you need = 1000×0.25×10^6/(4.2×10^6)=59.5ul. Make up the volume 30ml by adding media.
Priyobrata Sinha, you need to multiply your answer by 30 and then add enough media (28.21ml) for a total volume of 30ml.
- Badges
- Science topic
- Similar topics
- Biological Science
- Immunology
- Antibodies