All right. Thank you, ladies and gentlemen. Please be seated. All right. Let the record reflect we have been rejoined by all the members of our jury panel. Dr. John Gerdes is on the witness stand now undergoing cross-examination by Mr. Clarke. Mr. Clarke.
Good morning, ladies and gentlemen.
THE JURY: Good morning.
CROSS-EXAMINATION BY MR. CLARKE
Your Honor, if I may I would like to use People's exhibit 259, the Bronco results board.
Dr. Gerdes, this particular results board, People's exhibit 259, have you had an opportunity to either see this board or a recreation or copy of the board, if you will?
I have seen brief--brief glimpses of this on TV coverage. I have not seen a copy in other--any other manner.
All right. I would like to refer your attention, if I could, to what is labeled exhibit no. 30, center console.
And in particular, there are results from the Department of Justice in both the DQ-Alpha and D1S80 markers; is that right?
All right. Is it your testimony, Dr. Gerdes, and are you telling the ladies and gentlemen of this jury, that the DNA in that particular stain could not have come from the Defendant, Mr. Simpson?
I am saying that due to the way in which these samples were handled, the testing that was conducted in that lab, subsequent testing in that lab, is a possibility of cross-contamination.
Referring you to item no. 31, the center console, are you familiar with the results that were obtained by the Department of Justice as to that stain?
And results were obtained that included a 1.1, a 1.2 and a weaker 1.3 and 4; is that right?
With regard to the D1S80 results at 24 and 25, those are consistent and could have originated from Mr. Simpson; is that right?
All right. Can Dr. Gerdes take his seat back or are you going to need anything else? Mr. Clarke?
Dr. Gerdes, you described having visited the Department of Justice DNA laboratory in the past, correct?
With regard to the Department of Justice, they have a one-way flow of evidence; is that right?
You described yesterday that in your opinion evidence at the Los Angeles Police Department was brought back following amplification into the same area that it started out in prior to or at the time of extraction, correct?
You testified yesterday that following amplification of DNA, amplified DNA, that is, was brought back to the Los Angeles Police Department in the same area, correct?
I stated that it was brought back to that same location. It is not specifically the same room, but it is the same location.
I believe the extraction room is in a--is down a hall and in a large room near the entrance of the building and the amplification room would be a different room. You know, basically in the same building, though.
Okay. What are they separated by? How many feet, approximately, Department of Justice?
I'm sorry, your Honor. I do have one more exhibit I would like to use, the photo board which I believe is exhibit 281.
Mr. Wooden, when you bring that one up, can you just show it briefly to counsel, so they can familiarize themselves with what it is.
Yes. All right. We have seen that one before yesterday. Mr. Scheck, your client wants to see that.
Now, Dr. Gerdes, if I could ask you to step down from the witness stand and I'm going to refer you to what are the three photographs at the bottom of the diagram that are labeled "Piper Tech product gel electrophoresis."
In your opinion is that the same area as DNA extraction is conducted at Piper Tech as reflected in the top three photographs?
In your opinion is that the same area, that is the product gel electrophoresis area, as the extraction area?
So Dr. Gerdes, when you testified yesterday that that material was brought back to the same area, were you incorrect?
I don't believe so because there is another aspect that we didn't really specifically go into because I didn't want to go into a lot of detail, but at that amplification room at Piper or at Parker, excuse me, that is where they autoclave all their solutions and it is maybe five feet from the area where the amplification room is from--just across a very small little hallway.
Yesterday you described these materials as being brought back to the same area at Piper Tech, correct?
Today you have conceded that in fact those areas, that is, the extraction room and the product gel electrophoresis room, are not the same area, correct?
Now, in your opinion you have had contact with work done by Gary Sims at the Department of Justice; is that right?
And in fact you have reviewed, not only as a result of this case, but as a result of at least one other case, work done by Gary Sims, correct?
That work--I'm sorry. The work that you reviewed has included work that included PCR D1S80 typing, correct?
With regard to actually performing forensic DQ-Alpha analysis as well as D1S80 analysis, do you believe you are more qualified than Mr. Simpson to conduct that testing?
I don't think there is a--it wouldn't be difficult for me to do that test. I don't think that either one of us would be more qualified than the other.
Are you familiar with the experience that Mr. Sims has in conducting PCR typing on forensic samples?
How many times have you conducted a PCR analysis on evidentiary materials, such as in this case?
Incidentally, with regard to the Department of Justice, it is your opinion, is it not, that they have an excellent handle on contamination as far as their PCR testing?
It is my opinion that every PCR lab has a problem. I feel that they do an adequate job of attempting to limit that in their lab.
Now, I would like to turn your attention, if I could, to your employment before you came to work for, and can we call it IAD?
And as part of that teaching did you conduct instruction by television in the areas of physiology, anatomy and biochemistry?
I taught a class of anatomy and physiology on television. The biochemistry was not a TV class, but I taught biochemistry.
Referring to the TV teaching, you would be in front of a camera and students could watch your teaching, what, in other parts of the Hawaiian island?
I was employed by the veterans administration in Denver, Colorado, at the--in charge of the MS Center.
Now, Dr. Gerdes, shifting your attention--and you described the fact yesterday that you have written in the area of DNA; is that right?
All right. Could you describe for the jury how many of those publications are about forensic stain analysis?
Do you have any publication that deals with the area of PCR contamination in forensics?
Have you written any publication about the unsuitability or why PCR shouldn't be used in forensics?
Well, I consider my testimony to be public record and I have done that 23 times and I feel that is the best way.
How many publications have you written, Dr. Gerdes, describing why PCR shouldn't be used in forensics?
You have made presentations to people, and I'm talking about like a lecture format, about forensic evidence analysis, correct?
And those are the only presentations about forensic DNA analysis that you have given?
Did you attend, for instance, the last annual meeting of the American Academy of Forensic Scientists?
Have you attended any--well, first of all, are you familiar with the fact that DNA meetings are put on by, for instance, the Bureau of Investigation?
Your Honor, I have an objection to this. Perhaps we need to approach the side bar.
Let me actually withdraw that question and ask another question. Have you attended any meeting put on by a forensic organization?
Not specifically by a forensic organization. I have attended meetings where forensic topics were included as part of a broader meeting.
Well, there are conversations in terms of cases that I am involved with, so Ed Blake, for instance, Mark Taylor, Ben Grunbaum, Simon Ford to name a few.
Umm, I had some conversations just with regard to communications with regard to sending me photographs and things like that.
Are you aware that Dr. Blake was present during testing by the Department of Justice in this case?
Did you communicate with Dr. Blake about any of what he observed about this case in terms of testing by DOJ?
So in other words, you didn't have any regular communications whatsoever with Dr. Blake about what he may have seen going on during testing at DOJ?
He--he was the individual who accompanied me for the visit to the LAPD and took the photographs.
Does Dr. Grunbaum perform any forensic case work, analysis on case work, to your knowledge?
Have you had any class, been to any workshop whatsoever, in the collection of physical evidence in a criminal case?
Is it true that you have no personal experience whatsoever in the collection of physical evidence?
Have you conducted any validation studies involving the--I'm sorry--the analysis of forensic samples?
It is true, isn't it, that you have conducted no experiments in the forensic area?
You have done no studies to determine the effects of sunlight, rain, moisture, et cetera, on crime scene samples; isn't that correct?
As far as this area of forensic DNA analysis, your role is reviewing data from other labs that have conducted testing, correct?
I believe I have expertise that speaks to that due to my experience in observing what is going on, reading the forensic literature and other cases I have been involved with, yes.
Haven't you previously testified that you do not consider yourself an expert in the analysis of evidentiary material using DNA?
Do you believe you are an expert in physically--and I'm sorry--analyzing evidence using DNA typing?
Is it correct that your only connection with forensic cases is reviewing another laboratory's work usually at the request of a Defense attorney?
So is it correct then every time you have been retained to look at evidence in an individual case it has been to try to keep that evidence out?
Isn't it correct, Dr. Gerdes, that every time you have been retained to review another laboratory's work it has been with the intent, if possible, of attacking that evidence?
That's true. Sometimes cases are--due to the strategy of the particular case I'm not asked to come in and testify.
Is it correct that sometimes as a result of your review a Defense attorney doesn't call you as a witness?
And in each of those testimonies you have described your opinion about difficulties with PCR, correct?
Now, the laboratories--and I believe you said you have been retained about thirty times or was that an exact number?
Okay. Is it correct that most of those times it has been to review work done by Dr. Blake?
Umm, I wouldn't say most of the time. I would say maybe a third of the time at this point.
And did you testify to your opinions about the unreliability of results obtained by Dr. Blake?
And in particular the reliability of the results reported by Dr. Blake in those cases, correct?
The testimony goes to expressing and explaining the potential risks of this technology.
Well, on those prior occasions didn't you testify to twelve or more jurors, including alternates, and were trying to give them reasons why they shouldn't believe the results?
Your Honor, at a certain point I may request a side bar on this line of questioning.
As far as your testimony in this particular case, haven't you testified to the same things that you've testified to 23 times before?
I've been very consistent. This technology has some--some risk with it and I think it is important for the jury to know about those so that they can make a reasonable decision as to how much weight to put on this kind of evidence, and yes, I've always testified to that fact.
KEY QUOTEThat is a very--that is a more recent type of gene system. I would--without looking it up, I would guess probably four or five times.
And in those instances have you testified about why those results or results obtained using polymarker shouldn't be believed by a jury?
Have you testified in those instances about your concerns about the reliability of results obtained using polymarker?
Polymarker is another PCR system. It is susceptible to the same arguments, the same reservations, yes.
And in those instances have you again testified about your opinions about the unreliability of the use of that genetic marker?
I testified to the risks that need to be considered in any PCR-based testing system.
Dr. Gerdes, could you describe for us, please, how many times have you personally conducted just the PCR process itself, this amplification process, at an actual bench, lab bench?
Most of the testing that is done in our lab by PCR right now is done by technicians who are under my direction. I probably have personally done on the order of a hundred or so or more.
And in fact you testify, do you not, and I mean in areas--well, let me rephrase that. Did you ever testify, as a result of your laboratory's work, in areas other than forensic stain analysis like this case?
When you testify in that regard do you testify based on the results obtained by your analysts or technicians?
In other words, you didn't personally do the work in those cases wherein you ultimately testify?
That's correct, but I'm responsible to review the work and we have--if you have appropriate controls, you can look at the documentation of this kind of testing and determine if it was done correctly, if the controls look right, you have photos to look at and so forth, and pick up problems, so that is my responsibility.
And in fact this process of reviewing the work of a technician, that is the same thing that occurred in this case with regard to Cellmark, for instance?
As far as the in manner which Cellmark conducted testing, are you familiar with that testing in this case?
Yes. For instance, who were the bench analysts who conduct the actual physical testing at Cellmark?
In other words, they physically conducted the testing as far as using the reagents, conducting electrophoresis, if that was part of an individual process, and so forth, correct?
And in this particular case are you familiar with the fact that Robin Cotton testified as an expert?
You have had contact with her before as a result of your review of work done by Cellmark diagnostics?
Dr. Cotton in this case testified based on her review of the work conducted by her analysts, correct?
You described yesterday, Dr. Gerdes, the fact that your laboratory charges $100.00 an hour for your work in this case; is that right?
Does that include all of the time you've put into this case up to today and right now?
Can you estimate for us the amount of money that your laboratory is owed as a result of your work, including today?
I don't have the figures, so it depends on how long I undergo--I mean how long this goes on.
If I remember correctly, I was first phoned or called in September, either September or October.
You have reviewed all the typing strips at the Los Angeles Police Department through approximately May of `93 through August of `94, correct?
You also reviewed--let me phrase it as a question. Did you review all of the documentation from the Department of Justice in this case?
That is probably a little less than the Department of Justice material; is that right?
You described the fact--well, let me rephrase that, if I may. What year did you begin with the laboratory, IAD?
You described the fact yesterday that there is a replacement for you that takes your place when you are either gone or working on other cases, that is, criminal cases?
Well, not specifically. It is not like they hire someone to come in. Basically there are three individuals who are directors of this laboratory, we are all directors, and while I am gone someone has to take over those responsibilities. They take over.
Can you tell me a yearly figure for a hundred dollars an hour so that I can make it easy for me?
Let's sake an eight-hour day, that is about $800.00 a day, and how much would that be a week?
Well, okay. I work seven days a week. Okay. So 4000, so okay, we are talking about--
Okay. Can you estimate for us approximately how much your laboratory has profited--how much money they have taken in from your testimony and work in criminal cases? Is there anyway you put a rough estimate total?
Over the five years, umm--umm--perhaps somewhere on the order of 80,000 or maybe a hundred thousand, over five years.
So is it correct then that your laboratory is billing approximately two times or twice as much as you make when you are at home working in the lab?
All right. Dr. Gerdes, I would like to shift your attention to RFLP typing. You are familiar with it, correct?
It was developed by Sir Alec Jeffries in London along with Dr. White working independently?
Well, the underlying scientific principles actually are traced back to an individual named southern who developed the southern blotting technique and those individuals you mentioned were involved in the first to apply it for forensics.
Well, diagnosing a disease that might kill a person, that is a life and death matter, isn't it?
It is primarily used in genetic--diagnosing genetic diseases and in the--looking at certain gene alterations involved in some cancers.
It is used to look at, for instance, whether a person suffers from cystic fibrosis, right?
It is used to determine, for instance, whether or not a person has muscular dystrophy?
It is used as to whether or not tissue can be transplanted, as you described yesterday, from one person to another?
Does that ever involve, for instance, making interpretations on bands that might not look exactly like another band from another sample?
Incidentally, when you have conducted a paternity test, does that involve numbers at all when you report results?
In other words, you calculate a statistical probability, or whatever term, to describe how unusual it is to see these two samples matching, for instance, from a child and an alleged father?
We calculate that using what is called baysean statistics which is different than what is used in a forensic setting, but it is statistics.
IAD doesn't use RFLP typing in any forensic work that is done by anyone in the laboratory, correct?
Dr. Gerdes, are you offering an opinion to this jury that forensic PCR typing doesn't produce accurate results?
The PCR process itself, the method of amplifying DNA is a sound scientific principle, but the way in which it is currently--basically my opinion is it is inadequately controlled in forensic testing at the moment and it hasn't been adequately validated for that technology transfer. That is my testimony.
Dr. Gerdes, in your opinion then is PCR also not appropriate to use to exclude people in forensic cases?
The potential error, in my opinion, of additional dots due to contamination could just as likely cause a false exclusion as inclusion.
As you are using the term "Inclusion and exclusion," what do you mean, just to make sure we are talking the same language?
Well, "Inclusion" would mean that you match a sample with an individual that results in them being accused of a crime, in this sense, and "Exclusion" would be that due to that testing you would come up with a result that would say that they could not have done it.
You do hold the opinion that the use of PCR in medical uses, however, is sufficient in terms of sufficient reliability to be used to produce accurate results?
I do, based on all of the things we talked about yesterday where we discussed all of those items in terms of technology transfer and the relative risks of the two.
He is sitting right--second individual over on the first row behind the desk there.
Isn't it correct, Dr. Gerdes, that your view that PCR is okay to use in medical uses is due to the number of genetic markers that are available to test and the fact that you can confirm those results with other tests?
Is it correct that it is your belief that PCR is acceptable to use in medical diagnostics or medical uses--
Is it correct, Dr. Gerdes, that your opinion about the scientific acceptance in terms of why you believe it is appropriate to use, and I'm referring to PCR in medical diagnostic uses, is based on the number of genetic markers you can look at? Is that one reason.
When you feel--and you offered the opinion that the use of PCR in medical uses is appropriate, correct?
There are a variety of specific applications. The ones that we use in my lab are the detection of infectious agents such as cytomegalovirus or chlymadia and the typing of HLA for the purpose of bone marrow transplant where you know you were working with a sample from a given individual.
When you attempt to diagnose--and that is what you do, use PCR to attempt to diagnose the presence of CMV?
Is there any significance to looking at multiple markers in an individual sample in the medical arena?
As far as criminal cases, do you feel it is a good idea to look at more than one marker?
As far as PCR, is it correct that there are thousands of U.S. laboratories using PCR?
Life and death decisions are made based on the results of PCR typing everyday, correct?
PCR is used to find out, for instance, if food or dairy products have organisms in them that shouldn't be there, right?
I am not aware of that. Certainly it is used to diagnose whether or not fetuses have diseases?
It is used to diagnose many, if not most, of the same diseases that RFLP typing is used today or was previously used; is that right?
Incidentally, as far as disease diagnosis and--you have some experience in that area, correct?
In other words, it isn't always either there a real clear answer that the person has it or there is a real clear answer that the person doesn't, right?
And there are some diseases where there is a gray area in between those two; isn't that right?
And the results of those uses of PCR are utilized by doctors to counsel people on whether they have a disease, correct?
In those specific--this situation that you have set up they would obviously look at other clinical factors to try and make a determination. That would be one aspect of their decision in terms of their diagnosis is.
Isn't it true that in many of those instances, doctor, you have to counsel patients when they have to tell them you may or may not have this disease?
Is that a significant decision, in your viewpoint, as to what the patient decides?
Now, this technology involving PCR has been used to identify American war dead, correct?
Isn't it true Cellmark was the laboratory that performed this testing for the United States government?
Your Honor, I--if we go further along these lines I think it is cumulative and 352 objection.
Is it correct, Dr. Gerdes, that there are over 14,000 publications on the use of PCR, scientific publications?
Is it your opinion that there is no self-respecting molecular biologist alive who doesn't use PCR right now?
KEY QUOTEThat was--well, let me rephrase that. Already in place in your laboratory were RFLP techniques, correct?
Your laboratory then has used PCR either in a development phase or in an actual case work phase then for about seven years; is that fair?
Is it correct that most of the current work that your laboratory performed is done by PCR?
What percentage would you estimate of the case work at your--well, let's broaden it out. What percentage would you estimate of all the work conducted in your laboratory is done by PCR?
Where you report out results following the use of PCR in the areas of, for instance, whether a person has CMV?
That's correct. It wouldn't be thirty percent of the CMV diagnosis. The problem is certain techniques use PCR and we use them for that, and other techniques use other scientific methods and we do a wide range of different tests.
It is a difficult diagnosis in terms of traditional methods. I feel that PCR has made it--our quantitative PCR, once it was adapted to a quantitative method, has made that diagnosis more reliable.
As far as this virus use of PCR and--let me rephrase that if might. In your views of PCR to diagnose this virus, are you looking for levels of virus as opposed to whether a particular allele is present?
So you are looking for a range and make a decision within that range whether or not the virus is there?
Do you have to make any subjective interpretations about the levels as far as making a conclusion whether the person has it?
It is an objective conclusion based on a standard curve that we have derived and the methodology we have derived so that we can precisely measure levels of the DNA from CMV.
Incidentally--and I'm not sure the term came up yesterday, but it may have, but one of the instruments used in PCR frequently is called a thermalcycler; is that right?
We have also--and you are aware of testimony, are you not, about a corporation referred to as Roche?
And in fact Roche manufacturers the typing kit used in this case for DQ-Alpha, polymarker and the other PCR marker in this case, D1S80?
I don't know the details, but basically Roche holds the licensing--the patent, if you will, for the PCR process and they have negotiated a marketing agreement through Perkin Elmer for Perkin Elmer to market the kits that Roche develops.
So your laboratory bought this thermalcycler from Perkin Elmer who is related to Roche, correct?
The one we use is called a 9600. There are other models, but that is the one that we have.
Incidentally, when your--well, let me rephrase it. Your technicians use the thermalcycler, correct?
Do they change gloves between every sample that they touch when they put in the samples?
The tubes are in strips so that after you have placed them--I mean, once you have headed the tube, then you put it in the thermalcycler, you are carrying like a rack of tubes that are placed in there.
When they place tubes, individual tubes into the thermalcycler, do they change gloves between each tube?
Same exact thermalcycler that you have in terms of the model and its capabilities?
I think they have the 480, if I remember correctly, which is the model that preceded the 9600.
Is there anything in your opinion about the model 480 that is unreliable, as opposed to the 9600?
Incidentally, you also described bone marrow transplant tests that are performed in your lab, correct?
The national registry requires, for purposes of inclusion in this registry, PCR typing be done, correct?
And in particular they require that a particular genetic marker region be used to conduct that typing, correct?
It is not the same--it is not DQ-Alpha. It is another HLA gene. It is called DR-beta.
It is part of that complex, but there are more than one gene in that complex so it is not the same gene, but it is in the same area.
Is it correct then that the DQ-Alpha gene is in the same area as the exact gene that you test in your laboratory for bone marrow typing?
And I think you may have mentioned DR as well. Are these just different particular genes that are located close to one another?
Isn't it correct that by testing more than one gene you increase the likelihood of your finding important information in your work in your laboratory?
Do you use PCR for any other purposes other than bone marrow transplant information and looking for CMV?
We are very close to using it for the purpose of looking at donors, as I explained the other day, in terms of looking for infectious agents in donors.
Incidentally, as far as the actual process of conducting PCR typing amplification and then typing that process in a broad sense is the same whether it is medical or forensic, correct?
The basic set-up of the method in terms of how it is set up, that is the same, yes.
Is it your testimony that you have never conducted any case work analysis on a degraded sample?
As far as the use of PCR in other laboratories, and let's go outside criminal cases and forensics, isn't it correct that PCR is used on degraded samples?
I'm sorry, I misunderstood your question then. I'm having a hard time thinking of one.
Okay. Are you aware of the use of PCR, for instance, in the study of endangered animals.
Are you aware of the use of PCR--well, you are aware of the use of PCR to identify remains of war dead, correct?
Isn't it correct that PCR was used on, for instance, soldiers who were brutally killed in the Persian Gulf war?
All right. Isn't it true that with regard to that usage that those are bodies have been violently killed out in the desert?
Would you consider a body that has been out in the desert for hours or days degraded?
You described, for instance, the use of this--I'm sorry, let me rephrase that question. Your work in your laboratory is mainly with infectious materials as far as PCR, right?
Well, we do both infectious materials as well as HLA typing and those I don't think would be considered--the registry individuals are not considered to be infectious. Of course you handle everything as though it is potentially infectious.
Is PCR used to, for instance, type the presence of certain diseases in samples that have been obtained during a biopsy, for instance, a portion removed from a person's body?
And in fact those samples are frequently sent out for PCR typing to determine whether or not there is a disease or infection there, right?
In the normal process of doing what is called pathology, tissue samples are frequently imbedded with this wax or paraffin that allows you to cut sections and put them on a microscope slide and see the morphology, the architecture of the cells, and pathologists then can look at that and determine disease states.
I wouldn't consider it degraded. They are basically fixed and then imbedded with this paraffin and the process itself results in cross-linking of the protein in the sample to the DNA so that it is very difficult to extract the DNA after that.
Well, you say you wouldn't consider it degraded. These can be samples that are years old, can't they?
Yes, but they are fixed and imbedded in paraffin. That pretty much preserves them.
Well, is it your testimony that those samples that are preserved in paraffin the DNA is in exactly as good a form as it was when it was removed?
There is no degradation in that section. When you try and extract the DNA, because of the cross-linkage, you get DNA that has been--is in smaller pieces, but it is not due to any kind of contamination with bacteria that eat it, nothing like that.
And that is taken from women as part of an analysis, correct, or for purposes of an analysis?
That sample, while not sterile, is still tested to determine whether or not there may be a disease present in that individual?
What you are misunderstanding is you are testing for an infectious agent in that you are not testing for a specific human gene, so you are looking for the contaminant in this case.
The presence of those variety of contaminants doesn't stop that sample from being tested for the disease that is being looked for, correct?
The PCR is very precise and you design it so that you are only looking for the specific microorganism you are interested in, such as chlymadia which we do in our lab. That particular PCR will not detect herpes or a variety of other things that perhaps might be in that sample. It is designed to very specifically look for only the chlymadia organism.
So in other words, one of the important components or parts of PCR typing is designing it to look for what the scientist is trying to find?
That is true, and if you have a system that looks just simply for human DNA, that is where the problem comes in.
As far as known samples in your lab, do you use any cards? By "Cards" I mean a card that a portion of a liquid blood sample would be poured onto so that it can be used in that form?
I also believe there are some--some areas where they are doing that, looking for infections perhaps--I have read papers on hepatitis, for instance, where they will do that. But again, you are misunderstanding. In that case you are looking for the hepatitis organism so you have a specific mechanism--
And it can degrade to the point where there is no activity left or the DNA perishes, for lack of a better term?
Well, degradation just simply means that due to whatever reason--the DNA is a long stringy molecule that starts getting chopped up into smaller and smaller pieces. Ultimately you end up with such small pieces that when you attempt to analyze it you can't.
Focusing on samples--and let's just take a bloodstain, for instance, that is outside. Something on the outside can be exposed to sunlight, yes?
I've been very consistent. This technology has some--some risk with it and I think it is important for the jury to know about those so that they can make a reasonable decision as to how much weight to put on this kind of evidence, and yes, I've always testified to that fact.
I guess not.
None of them.
Is it your opinion that there is no self-respecting molecular biologist alive who doesn't use PCR right now?
Is he present in the audience? ... Where is he?