Judgment of the Supreme Court, Bronx County (Robert Cohen, J.), rendered April 6, 1989, convicting defendant, after a jury trial, of criminal sale of a controlled substance in the third degree (Penal Law § 220.39 [1]) and sentencing him, as a second felony offender, to a term of imprisonment of from 4 Vi to 9 years, affirmed.
Defendant was arrested in a buy-and-bust operation subsequent to his sale of four vials of cocaine to an undercover police officer for prerecorded buy money. The officer testified that he initialed, in pen, the top of the vials and placed them in an envelope, which was sealed and signed by him and then cosigned by a sergeant. At trial, the undercover officer testified that the vials, which were introduced into evidence, were in substantially the same condition as they were when placed in the envelope. A police chemist testified that she received the vials in a sealed envelope and that she broke the seal herself. This evidence provides a reasonable assurance of the identity of the cocaine and its unchanged condition (People v Julian, 41 NY2d 340, 343; People v Newman, 129 AD2d 742). When the vials were introduced into evidence, they did not contain any initials. However, this discrepancy is an issue going merely to the weight of the evidence (People v Newman, supra; People v Ramos, 147 AD2d 718).
The circumstances of People v Ruiz (162 AD2d 350), upon which the dissent relies, are distinguishable. In that case, the testimony of the undercover officer who purchased the vials of cocaine was full of inconsistencies. His report of the buy-and-bust operation had been altered, he was unable to provide a coherent account of when and why the alteration was made, his description of the vials did not match those admitted into evidence and, finally, his signature did not appear on the security envelope in which the evidence was stored. We therefore held that the jury’s verdict was against the weight of the evidence and vacated the conviction for criminal sale of a controlled substance.
In the case before us, by contrast, the only discrepancy in the evidence is that the undercover officer’s initials did not appear on the vials when they were admitted into evidence. The jury was free to conclude that the initials, marked on the vials only in pen, were rubbed off in handling. Thus, the *329verdict cannot be said to be unsupported by the evidence (see, People v Bleakley, 69 NY2d 490). A chain of custody was properly established.
The record does not reflect any discrepancy with respect to the presence of tape on the vials. Upon direct examination, the following colloquy took place:
"Q. Officer, are the vials in the same envelope that they were on the day that you signed and sealed? "A. Yes. "Q. Is there a slit oh the side for analysis purposes? "A. Yes. "Q. And are they— "Are the vials now in an envelope in a sealed clear plastic bag? "A. Yes. "Q. Were they? "A. Yes. "Q. And the vials have tape on them; is that correct? "A. Yes. "Q. Are the vials themselves, Officer, in substantially the same condition now as they were on February 9, 1988? "A. Yes.” The jury was free to discount the testimony given by the lab technician. However, assuming the jury credited her testimony to the effect that she specifically recalled the subject vials out of the thousands or so similar vials she handled during the week, it is nevertheless entirely consistent with the undercover officer’s testimony as reflected in the record.
Finally, the undercover officer’s testimony regarding the description of the seller which he gave to the arresting officers by radio does not constitute bolstering in violation of People v Trowbridge (305 NY 471; see, People v Candelario, 156 AD2d 191; cf., People v Luciano, 64 AD2d 614). This testimony, together with that of the arresting officers who received the description, provides a necessary explanation of the events which precipitated defendant’s arrest (see, Matter of Robert S., 159 AD2d 358, appeal dismissed 76 NY2d 770). Concur—Sullivan, J. P., Asch and Rubin, JJ.