OPINION
¶ 1 The issue befoi’e us is whether the Confrontation Clause of the Sixth Amendment to the United States Constitution is violated when a testifying expert offei’s an opinion on the similai’ity of DNA profiles prepared by technicians who did not testify. We conclude that the expei’t’s testimony did not contravene the Confx’ontation Clause.
I.
¶ 2 In 2006, Joseph Wesley Gomez was arrested and charged with ci’imes related to a home invasion. Police collected items from the crime scene and submitted them, along with a blood sample taken from Gomez, to a labox*atoxy. The laboratoxy analyzed DNA from the items and compared the results with the DNA from the blood sample.
¶ 3 In pei’forming DNA testing and analysis, the laboratory used an “assembly line” method that involved seven steps. During the fii’st six steps of the px’ocess, technicians isolate and amplify the DNA and genei’ate pi'ofiles. The technicians do not interpret data or dx’aw conclusions during these first six steps, in which machines ai’e used for evex’y step except the initial scx’eening of submitted items for DNA, 1 Vaxious technicians involved in the laboratoxy pi’ocesses did not testify at Gomez’s tidal.
¶ 4 The State instead called a single witness about the DNA testing. That witness, a senior forensic analyst and supervisor at the laboratoxy, testified in detail about the laboratory's operating procedures, standards, and safeguai’ds. Although the analyst had not witnessed all of the steps in the process, she had checked the technicians’ records for any deviations from the laboratory’s protocols. The analyst had pei’foi’med the initial evidence screening and DNA extraction on most of the items, and she testified about the chain of custody for all items. For each sample, the analyst personally performed the final step in the pi’ocess, intei’pretation and comparison. This step inquired her to compare the DNA profiles generated in the laboratoxy, and it was the only step involving human analysis.
¶ 5 The analyst testified that several px-ofíles dexáved from evidence at the exime scene “matched” the profile obtained from Gomez’s blood sample. 2 The data from the testing px-oeess were not introduced into evidence as exhibits.
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¶ 6 Gomez was convicted of the charged felonies. The court of appeals affirmed, rejecting Gomez’s argument that the expert’s testimony violated the Confrontation Clause.
State v. Gomez,
1 CA-CR 08-0318,
¶ 7 We granted review because the application of the Confrontation Clause to expert testimony about DNA profiles is an issue of statewide importance likely to recur. We have jurisdiction under Article 6, Section 5(3) of the Arizona Constitution and A.R.S. § 12-120.24 (2003).
II.
¶ 8 The Sixth Amendment guarantees that “[i]n all criminal prosecutions, the accused shall enjoy the right ... to be confronted with the witnesses against him.” U.S. Const. amend. VI. The “primary object” of the Confrontation Clause is “testimonial hearsay.”
Crawford v. Washington,
¶ 9 In
Melendez-Diaz v. Massachusetts,
- U.S. -, -,
III.
¶ 10 Gomez contends that because the laboratory technicians who generated the DNA profiles did not testify at his trial, the analyst’s testimony violated the Confrontation Clause. In assessing Gomez’s argument, it is useful to separate the analyst’s testimony into two parts: (1) her testimony regarding the laboratory protocols and the generation of the DNA profiles and (2) her expert opinion that several of the profiles matched.
See Pendergrass v. State,
A.
¶ 11 Gomez correctly does not argue that the analyst’s testimony about her role in the testing process, the laboratory’s procedures, and the qualifications of the technicians was hearsay. This testimony was based on the analyst’s personal knowledge. Rather, Gomez argues that the analyst’s testimony about the DNA profiles was hearsay because she was not involved in generating those profiles.
¶ 12 It is not clear that the data in the machine-generated DNA profiles were hearsay statements. In
United States v. Washington,
a divided Fourth Circuit held that printed data from a gas chromatograph were not hearsay statements and therefore the Sixth Amendment was not offended when the data were introduced into evidence without offering the testimony of the technicians who operated the machine.
¶ 13 We also note that the profiles were not introduced into evidence as exhibits at Gomez’s trial; the analyst simply testified about them. In
Banville,
the Massachusetts Supreme Judicial Court held that the Confrontation Clause is not offended when an expert relies on testimonial hearsay to form an opinion so long as the expert does not testify to the details of the hearsay and the hearsay itself is not admitted.
See Banville,
¶ 14 In considering Gomez’s argument that the analyst’s testimony about the profiles violated the Sixth Amendment, we start from the premise that the Confrontation Clause does not require that every person in the chain of custody be available for cross-examination.
Melendez-Diaz
expressly rejected the notion that “anyone whose testimony may be relevant in establishing the chain of custody, authenticity of the sample, or accuracy of the testing device, must appear in person as part of the prosecution’s ease.”
¶ 15 Gomez does not contend in this Court that the chain of custody of the DNA samples was insufficiently established. Police officers testified that the evidence was collected and sent to the laboratory, and the analyst testified that the evidence was received, processed, tested, and returned. The analyst testified from her own knowledge not only about the laboratory’s general procedures, but also about the records kept by the laboratory in this ease. The chain of custody testimony did not violate the Confrontation Clause simply because every technician who handled and processed the samples did not testify.
See Melendez-Diaz,
¶ 16 The remaining question, then, is whether Gomez’s inability to cross-examine the technicians deprived him of his confrontation rights with respect to the analyst’s testimony about the profiles. If the DNA profiles are hearsay statements, they are in effect statements of the processing machine about the data contained in the samples. The profiles contain neither the opinion nor the statement of the technicians. The machine, of course, cannot be cross-examined. The issue thus is whether the Confrontation Clause was satisfied because the analyst, rather than the technicians, was available for cross-examination.
¶ 17 In virtually identical circumstances, several courts have held that the testimony of a witness with knowledge of how the profiles were prepared satisfies the Sixth Amendment. The Indiana Supreme Court’s decision in
Pendergrass
is particularly instructive. In that ease a laboratory supervisor testified regarding the processing of DNA evidence.
¶ 18 The defendant in Pendergrass contended that the certificates should not have *169 been admitted into evidence without the testimony of the employees who processed the samples. The Indiana Supreme Court rejected that argument, pointing out that the primary purpose of cross-examination is to test the reliability of a statement. See id. at 708. In Pendergrass, as here, the supervisor “would be a competent witness, perhaps the ideal witness, against whom to lodge such challenges,” because she “had personal knowledge of the laboratory’s work on the specimens at issue as the person who performed the technical review.” Id. The Indiana court distinguished Melendez-Diaz, noting that the defendant in Melendez-Diaz had no opportunity to cross-examine anyone “involved in the substantive analysis.” Id.
¶ 19
United States v. Boyd,
[o]nly the final stage of the DNA testing involved the type of analytical judgment for which a certificate would be an inadequate substitute for in-eourt testimony under the Sixth Amendment. But this was precisely where the Government provided live testimony in the form of the expert who performed this step.
Id.
¶ 20 Consistent with
Pendergrass
and
Boyd,
other jurisdictions have held that DNA profiles may be admitted at trial when the laboratory technicians who handled the samples and obtained the machine-generated data do not testify, as long as someone familiar with the profiles and laboratory procedures is subject to cross-examination.
See, e.g., Vann v. State,
¶ 21 We find the reasoning in these cases compelling. The technicians at most could have testified about the mechanical steps they took to process the DNA samples. The analyst was able to review that work, testify from her own knowledge as to the procedures used, and answer questions during cross-examination about the accuracy of the end results. The analyst’s testimony therefore did not offend the Confrontation Clause.
B.
1122 Regarding the analyst’s expert opinion, we repeatedly have held that the Confrontation Clause is not violated when an expert bases testimony on data provided by others who are not subject to cross-examination. We have held that a medical examiner may offer an expert opinion based on review
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of reports and test results prepared by others, as long as the testifying expert does not simply “act as a conduit for another non-testifying expert’s opinion.”
State v. Snelling,
¶ 23 As in
Smiling,
the analyst here did not act as a “conduit” for the opinions of others.
See Smiling,
¶ 24 The testifying expert in this ease was subject to cross-examination about her independent conclusion that several of the DNA profiles came from the same person. The analyst’s reliance on data obtained from non-testifying witnesses in arriving at her opinion did not violate the Confrontation Clause.
IV.
¶ 25 Gomez requested a jury instruction that “[t]he work of non-testifying witnesses is admitted only to allow the consideration of the reasons for the expert’s opinion.” He argued that the instruction was compelled by Arizona Rule of Evidence 105, which provides that “[w]hen evidence which is admissible ... for one purpose but not admissible ... for another purpose is admitted, the court, upon request, shall restrict the evidence to its proper scope and instruct the jury accordingly.” The trial court rejected the proposed instruction as a comment on the evidence. The court of appeals upheld the denial of the instruction on different grounds, finding the instruction legally flawed. Gomez, 1 CA-CR 08-0318 at ¶ 27.
¶ 26 The court of appeals correctly noted that a trial court generally does not have to separate the good from the bad in a proposed instruction.
See State v. Mitchell,
¶ 27 We nonetheless find no reversible error. Rule 105 applies only when the evi *171 dence “is admissible ... for one purpose but not admissible ... for another purpose.” Because the DNA profiles were not themselves admitted into evidence, the instruction Gomez requested necessarily related to the analyst’s testimony about the profiles. In contrast to Snelling, where testimony about the underlying data was offered only to support an expert opinion, the analyst’s testimony here about the DNA profiles was not so limited. The analyst testified as an expert on DNA, but also established the chain of custody, testified how the evidence submitted by the police to the laboratory was processed, and explained how DNA profiles were derived from that evidence. Her testimony thus was offered to demonstrate that the profiles were in fact generated from DNA obtained at the crime scene and from Gomez. Because the analyst’s testimony about the profiles was not submitted simply to support her expert opinion, a limiting instruction was not required.
V.
¶ 28 For the reasons above, we affirm Gomez’s convictions and sentences, but vacate ¶¶ 21-27 of the memorandum decision of the court of appeals.
Notes
. The evidence is screened initially by a technician for the presence of DNA. If DNA is found, it is extracted from the evidence and a machine measures its quantity. Copies of specific regions of the DNA are then machine generated. Machines then separate the DNA so that the alleles may be examined and determine which alleles are present. A software program processes that data and generates DNA profiles, which list the number of alleles present at certain spots within the genetic code. Finally, an analyst examines the generated profiles and compares them to known profiles.
. The analyst testified that the odds of finding a DNA match from someone other than Gomez for the DNA on each piece of evidence from the *167 crime scene ranged from one in thirteen thousand to one in 1.2 sextillion.
