Rab27A, Synaptic Systems, 168 013

Our team performed a comprehensive review of the scientific literature to identify studies using antibodies against human Rab27A and Rab27B, followed by extraction and evaluation of available data according to pAbmAbs rating criteria.

YCharOS conducted a systematic head-to-head comparison of 14 commercially available antibodies against Rab27A and 7 against Rab27B across multiple applications

Antibodies were tested by WB using lysates (40 µg total protein) from U-87 MG WT cells and cells with siRNA-mediated knockdown (KD) of Rab27A or Rab27B. The same cell lines were used for IF testing. In addition, antibodies were evaluated by IP using HAP1 (Rab27A) or U-87 MG (Rab27B) cell lysates (1 mg), following YCharOS standard protocols (see reference).

In Western blot (1:1000 antibody dilution), 168 013 detects a band at the expected size (~24 kDa) in WT U-87 MG lysate. In lysate from Rab27B KD cells, a band of comparable intensity is observed. In Rab27A cell lysate is observed a weaker band with a possible slight upward shift in size. Together, these results indicate that the antibody detects both Rab27A and Rab27B.

In IP, the antibody (2 µg) enriches the Rab27A signal compared to the starting material (U-87 MG cell lysate), with a reduced signal observed in unbound fraction, indicating some, but incomplete depletion of the target from the cell lysate. Rab27A in the starting material, unbound fraction, and precipitate was detected by WB using the antibody 95394 from Cell Signaling Technology. Antibody 168 013 was not tested in IF.

We highly encourage other scientists to share their observations.

This antibody works well for immunostaining Rab27A in primary hippocampal neurons from mice. 7 DIV neurons were fixed in 4% PFA and immunostained for Rab27B using 1:500 dilution in blocking buffer. Some background was observed.