Bio-Rad Immun-Blot® Opti-4CN™ Colorimetric Kits - Manual (Page 12)

Troubleshooting Guide (continued)
Probable Recommended
Problem Cause Solution
d. Little or no antigen i. Tween-20 may
is bound to the wash bound
membrane. antigen from
the membrane.
Eliminate
Tween-20 from
the assay
(except the
wash after the
blocking step).
ii. Transfer of pro-
tein onto the
membrane was
incomplete.
Stain gel to
assure transfer
of protein. Use
Prestained
Standards to
monitor trans-
fer efficiency.
Consult the
appropriate
instrument
manual for
proper proce-
dures and rec-
ommendations.
19
Troubleshooting Guide (continued)
Probable Recommended
Problem Cause Solution
c. Conjugate is inactive. i. Store the conju-
gate at the
proper temper-
ature. Avoid
repeated
freeze-thaw
cycles.
ii. The concentra-
tion of the con-
jugate was
non-saturating.
Increase the
concentration
of the conju-
gate used in
the assay.
iii.Conjugate
may be con-
taminated,
causing inacti-
vation of the
antibody or
enzyme. Tap
water may
cause inactiva-
tion; use only
distilled,
deionized
water to pre-
pare all solu-
tions.
18
4100130c.qxd 4/9/99 8:29 AM Page 18