Question

Please help calculate average CFU/ml

Treatment 1: BHI, 370c, +02 Time (min)oD (average) CFU/ml # of colonies 65, 118, 119, 13 8, 16, 13, o Dilution 0.11 E-6 E-7 15 30 0.12 0.19 E-6 E-7 97, 155, 213, 122 18, 8, 26, 10 45 60 0.31 0.51 E-6 E-7 224, 273, 156, 258 64, 44, 16, 66 75 90 0.88 52, 67, 96, TNTC 14, 5, 9, 93 0.98 E-7 E-8 105 120 1.07 E-7 E-8 400, 116, TNTC, 0 33, 19, 147,0 1.17 135 1.22 1.25 150 E-7 E-8 321, 226, TNTC, TNTC 40, 20, 43, 155 165 180 1.42 1.39 E-7 E-8 296, TNTC, TNTC, TNTC 52, 66, 41, 66

Answer 1

Time (min)	OD Average	Dilution	No of colonies	Cfu/ml
0	0.11	E-6 E-7	65, 118,119,13 8,16,13,0	7.8*107 3.7*108
15	0.12
30	0.19	E-6 E-7	97,155, 213,122 18,8,26,10	4.95*108 5.4*108
45	0.31
60	0.51	E-6 E-7	224, 273,156,258 64, 44, 16, 66	7.17*108 1.4*109
75	0.88
90	0.98	E-7 E-8	52, 67, 96,TNTC 14,5,9,93	TNTC 5.1*109
105	1.07
120	1.17	E-7 E-8	400, 116, TNTC , 0 33, 19, 147, 0	TNTC 4.9*109
135	1.22
150	1.25	E-7 E-8	321, 226, TNTC, TNTC 40, 20,43,155	TNTC 1.41*1010
165	1.42
180	1.39	E-7 E-8	296 TNTC, TNTC TNTC, 52, 66, 41, 66	TNTC 1.76*1010

                                                                                                             

Treatment 1: BHI. 37⁰C, +0₂

CFU/ml: colony forming unit = number of colonies* dilution factor

Volume of culture plated

OD =Optical density

TNTC = Too numerous to count, which is above 250 colonies in a plate, means colonies are not separated and are not significant.