How have the courts treated the prosecution's proffer by the prosecution of opinions rendered by qualified experts using scientifically accepted methods of analysis?

Cua fails to show how the proffer by the prosecution of opinions rendered by qualified experts using scientifically accepted methods of analysis constitutes a pattern of "egregious" misconduct, or an attempt to use "deceptive or *606 reprehensible methods" to persuade the jury. His claim is in any event forfeited by his failure to object at trial. " 'To preserve for appeal a claim of prosecutorial misconduct, the defense must make a timely objection at trial and request an admonition; otherwise, the point is reviewable only if an admonition would not have cured the harm caused by the misconduct.' [Citations]." ( People v. Gionis, supra, 9 Cal.4th at p. 1215, 40 Cal.Rptr.2d 456, 892 P.2d 1199.)