Bioassay
Bioassay
Bioassay
Seminar On
BIOASSAY OF DRUGS
Quantal
Graded
Quantalresponse: the response is in the
form of ‘all or none’, i.e. either no
response or maximum response.
Types:
For standard
Dose Log dose Response % response
(height) (cm)
0.1 -1 0.9 25.71
0.1 -1 0.9 25.71
0.2 -0.69 1.5 42.85
0.4 -0.39 2 57.14
0.6 -0.22 2.8 80
0.8 -0.09 3.5 100
1 0 2.3 65.71
For test
0.1 -1 0.7 20
0.3 -0.52 1.3 37.14
Maximum response (3.5) is considered 100% response.
For 0.9,
% 100
R
E
S
P 50
O
N
S
E
0
Log dose
Other methods which are based on the dose-response
relationship include 3 point, 4 point and 6 point methods.
The mean responses are calculated and plotted against log-dose and
amount of standard producing the same response as produced by the
test is determined graphically as well as mathematically:
n1 T - S1 n2 Cs
Conc. of Unknown = t X antilog S2 - S1 X log n1
Oxytocin Digitalis
1. Rabbit Head-drop Method :
Principle: d-Tubocararine hydrochloride is
injected into the marginal vein of a rabbit’s ear
till the rabbit’s neck muscles are relaxed such
that the animal cannot hold its head up. The
total amount of test sample required to produce
the endpoint is compared with the total amount
of the standard sample required to produce
similar endpoint.