= Seal leak current
{title2=$I_{\mathrm{seal}}=V_p/R_{\mathrm{seal}}$}
<Seal leak current> bypasses the membrane patch through an imperfect seal. For an ideal ohmic seal to a zero-voltage bath, $I_{\mathrm{seal}}=V_p/R_{\mathrm{seal}}$, positive from pipette to bath. At $|V_p|=50\,\mathrm{mV}$ and $R_{\mathrm{seal}}=1\,\mathrm{G\Omega}$ its magnitude is $50\,\mathrm{pA}$, far larger than the synthetic $0.8\,\mathrm{pA}$ single-channel step. A stable baseline can be subtracted, but changing leakage can mimic a biological response. Intrinsic membrane leak through <ion channels> is distinct from this bypass: interpreting both as the same <electrical conductance> obscures whether the <biological cell> or the seal changed.
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