# Growth promotion test

How to calculate recovery percentage of growth promotion test of new media. Please give me an example

1 Like

Factor 2.
Recovery Not less then 75%

P1 +P2 /2 =???

Exp. Culture suspension 65 cfu.

Gpt Plate count 60.
60×100=6000
6000/65=92%
92% Recovery

Newly receive media compair to previous batch media .
I.e growth support or not.

65 average count of two plate of old stock media and 60 average count of two plate new stock media which is gpt media… please clarify my doubt @rustam_shekh bhai

Factor 2 se dekho bhai 75% recovery ho rhi he to koi problem nhi .

65 and 60 Jo dikhaye h o bas samjha dijeye

for new consignment you have to old media also for compression.
growth on media plate divide by 2. it will be urs lower range for growth.
then after division on 2 the obtained result multiply by 4 it will be the high range.
so the new consignment of dehydrated media result should come in between in the lower and higher range.
for example. 84 is no of colony 84/2= (42 - 168)

Factor of two means *2 and /2… That is, if ur cfu count is 50 then recovered must be 25-100, its not 75%