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When Robert Lanza?s group at Advanced Cell Technology reported this week creating so-called ethically clean ES cell lines (establishing colonies from an early human embryo without destroying it) they didn?t make clear whether they had actually accomplished this feat. This work might have potential, but the numbers speak to a logical smoke and mirror show. Using 16 blastomeres (embryos in the 8-to-10-cell stage), Lanza?s group extracted 91 cells to create a total of 2 cell lines. 91 cells taken from 16 embryos means its quite likely that none of these embryos could have survived, and if they did, the chances that one of the two lines derived are actually from the survivor is next to impossible.

That means while Lanza can say, ethical problem solved, he hasn?t actually derived a cell line without destroying an embryo. That should have been the second line to every story covering this paper including ours, which has already attracted its share of comments.

The Nature press office offered a clarification to this point just minutes after the embargo lifted on what would be a major breaking story. It ran on the first page of the New York Times. And it likely should have raised hackles in newsrooms not only for its lateness, but for its vagueness:

Dear colleague,

We have been alerted to the fact that a sentence in our press release was incorrect. Where we stated

Using sixteen spare human IVF embryos, the team extracted one out of the eight to ten cells within each embryo and grew them in culture.

In fact it is true to say:

Of the sixteen embryos that were used some had one to two cells removed, as would be the case with PGD. However, some of the other embryos were biopsied multiple times.

The corrected press release is below.

Best regards,

The flurry of numbers and only distant relationship between the ?corrected? sentence and the original left us scratching our heads as to what exactly they meant. As if sensing they hadn?t aggravated reporters enough. They issued a second correction at 4pm on a Friday afternoon (long after the UK office had likely packed up and gone home). The second correction says what seemed apparent from the numbers. Bold emphasis is mine.

Dear colleague,

Apologies for the multiple mailings. It has come to our attention that the clarification of the press release on this week's stem cells paper was incorrect. This was due to internal communication problems.

A corrected version of the press release is below. We feel it necessary to explain that this paper demonstrates that human ES cells can be grown from single cells but that the embryos that were used for these experiments did not remain intact.

Further where we stated that some embryos had one or two cells removed and others were biopsied multiple times we hope to now provide the breakdown of each embryo used and how many cells were then used to generate stem cell lines. Please check the press site for updates.

The supplementary table with full details is available on the press site and the corrected press release is below.

Best regards,

Important indeed. That supplementary table was neatly tucked away on their press site. I?ve pulled the information out here. The first column is the experiment number. The second is the number of embryos used in that experiment and the third is the number of blastomeres they retrieved.

1 2 10

2 1 6

3 2 11

4 1 7

5 2 12

6 2 12

7 2 11

8 1 6

9 1 4

10 2 12

Total 16 91

Lines were established from the 3rd and 6th experiment. And while it would appear that not a single embryo would have had fewer than four cells removed from it, it is impossible to tell because of the way the embryos are grouped together. This is some murky number jiving that the Nature press office says they are looking in to. The fiasco at the press office could be forgiven perhaps if this weren?t such a hot button topic and if they had admitted the confusion and its source before embargo or at least before everyone headed out for the weekend. I couldn?t get the senior press officer on the phone despite several calls.